diff --git a/mypy/typeshed/stdlib/_codecs.pyi b/mypy/typeshed/stdlib/_codecs.pyi
index 44cc0f78028c..51f17f01ca71 100644
--- a/mypy/typeshed/stdlib/_codecs.pyi
+++ b/mypy/typeshed/stdlib/_codecs.pyi
@@ -104,35 +104,35 @@ if sys.version_info < (3, 8):
     def unicode_internal_decode(__obj: str | ReadableBuffer, __errors: str | None = None) -> tuple[str, int]: ...
     def unicode_internal_encode(__obj: str | ReadableBuffer, __errors: str | None = None) -> tuple[bytes, int]: ...
 
-def utf_16_be_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_16_be_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_16_be_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-def utf_16_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_16_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_16_encode(__str: str, __errors: str | None = None, __byteorder: int = 0) -> tuple[bytes, int]: ...
 def utf_16_ex_decode(
-    __data: ReadableBuffer, __errors: str | None = None, __byteorder: int = 0, __final: int = False
+    __data: ReadableBuffer, __errors: str | None = None, __byteorder: int = 0, __final: bool = False
 ) -> tuple[str, int, int]: ...
-def utf_16_le_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_16_le_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_16_le_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-def utf_32_be_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_32_be_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_32_be_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-def utf_32_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_32_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_32_encode(__str: str, __errors: str | None = None, __byteorder: int = 0) -> tuple[bytes, int]: ...
 def utf_32_ex_decode(
-    __data: ReadableBuffer, __errors: str | None = None, __byteorder: int = 0, __final: int = False
+    __data: ReadableBuffer, __errors: str | None = None, __byteorder: int = 0, __final: bool = False
 ) -> tuple[str, int, int]: ...
-def utf_32_le_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_32_le_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_32_le_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-def utf_7_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_7_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_7_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-def utf_8_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+def utf_8_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
 def utf_8_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
 
 if sys.platform == "win32":
-    def mbcs_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+    def mbcs_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
     def mbcs_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
     def code_page_decode(
-        __codepage: int, __data: ReadableBuffer, __errors: str | None = None, __final: int = False
+        __codepage: int, __data: ReadableBuffer, __errors: str | None = None, __final: bool = False
     ) -> tuple[str, int]: ...
     def code_page_encode(__code_page: int, __str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
-    def oem_decode(__data: ReadableBuffer, __errors: str | None = None, __final: int = False) -> tuple[str, int]: ...
+    def oem_decode(__data: ReadableBuffer, __errors: str | None = None, __final: bool = False) -> tuple[str, int]: ...
     def oem_encode(__str: str, __errors: str | None = None) -> tuple[bytes, int]: ...
diff --git a/mypy/typeshed/stdlib/_csv.pyi b/mypy/typeshed/stdlib/_csv.pyi
index 7d15365d3b02..7e9b9e4e7a79 100644
--- a/mypy/typeshed/stdlib/_csv.pyi
+++ b/mypy/typeshed/stdlib/_csv.pyi
@@ -1,9 +1,9 @@
 from _typeshed import SupportsWrite
 from collections.abc import Iterable, Iterator
-from typing import Any, Union
-from typing_extensions import Literal, TypeAlias
+from typing import Any
+from typing_extensions import Final, Literal, TypeAlias
 
-__version__: str
+__version__: Final[str]
 
 QUOTE_ALL: Literal[1]
 QUOTE_MINIMAL: Literal[0]
@@ -27,7 +27,7 @@ class Dialect:
     strict: bool
     def __init__(self) -> None: ...
 
-_DialectLike: TypeAlias = Union[str, Dialect, type[Dialect]]
+_DialectLike: TypeAlias = str | Dialect | type[Dialect]
 
 class _reader(Iterator[list[str]]):
     @property
diff --git a/mypy/typeshed/stdlib/_decimal.pyi b/mypy/typeshed/stdlib/_decimal.pyi
index 38b8ac30cc2f..b8208fe180a1 100644
--- a/mypy/typeshed/stdlib/_decimal.pyi
+++ b/mypy/typeshed/stdlib/_decimal.pyi
@@ -1,17 +1,16 @@
 import numbers
 import sys
-from _typeshed import Self
 from collections.abc import Container, Sequence
 from types import TracebackType
-from typing import Any, ClassVar, NamedTuple, Union, overload
-from typing_extensions import Literal, TypeAlias
+from typing import Any, ClassVar, NamedTuple, overload
+from typing_extensions import Final, Literal, Self, TypeAlias
 
 _Decimal: TypeAlias = Decimal | int
-_DecimalNew: TypeAlias = Union[Decimal, float, str, tuple[int, Sequence[int], int]]
+_DecimalNew: TypeAlias = Decimal | float | str | tuple[int, Sequence[int], int]
 _ComparableNum: TypeAlias = Decimal | float | numbers.Rational
 
-__version__: str
-__libmpdec_version__: str
+__version__: Final[str]
+__libmpdec_version__: Final[str]
 
 class DecimalTuple(NamedTuple):
     sign: int
@@ -69,9 +68,9 @@ else:
     def localcontext(ctx: Context | None = None) -> _ContextManager: ...
 
 class Decimal:
-    def __new__(cls: type[Self], value: _DecimalNew = ..., context: Context | None = ...) -> Self: ...
+    def __new__(cls, value: _DecimalNew = ..., context: Context | None = ...) -> Self: ...
     @classmethod
-    def from_float(cls: type[Self], __f: float) -> Self: ...
+    def from_float(cls, __f: float) -> Self: ...
     def __bool__(self) -> bool: ...
     def compare(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
     def as_tuple(self) -> DecimalTuple: ...
@@ -163,9 +162,9 @@ class Decimal:
     def rotate(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
     def scaleb(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
     def shift(self, other: _Decimal, context: Context | None = None) -> Decimal: ...
-    def __reduce__(self: Self) -> tuple[type[Self], tuple[str]]: ...
-    def __copy__(self: Self) -> Self: ...
-    def __deepcopy__(self: Self, __memo: Any) -> Self: ...
+    def __reduce__(self) -> tuple[type[Self], tuple[str]]: ...
+    def __copy__(self) -> Self: ...
+    def __deepcopy__(self, __memo: Any) -> Self: ...
     def __format__(self, __specifier: str, __context: Context | None = ...) -> str: ...
 
 class _ContextManager:
@@ -203,7 +202,7 @@ class Context:
         traps: None | dict[_TrapType, bool] | Container[_TrapType] = ...,
         _ignored_flags: list[_TrapType] | None = ...,
     ) -> None: ...
-    def __reduce__(self: Self) -> tuple[type[Self], tuple[Any, ...]]: ...
+    def __reduce__(self) -> tuple[type[Self], tuple[Any, ...]]: ...
     def clear_flags(self) -> None: ...
     def clear_traps(self) -> None: ...
     def copy(self) -> Context: ...
diff --git a/mypy/typeshed/stdlib/_heapq.pyi b/mypy/typeshed/stdlib/_heapq.pyi
index 90dc28deb71f..8d6c3e88103e 100644
--- a/mypy/typeshed/stdlib/_heapq.pyi
+++ b/mypy/typeshed/stdlib/_heapq.pyi
@@ -1,8 +1,9 @@
 from typing import Any, TypeVar
+from typing_extensions import Final
 
 _T = TypeVar("_T")
 
-__about__: str
+__about__: Final[str]
 
 def heapify(__heap: list[Any]) -> None: ...
 def heappop(__heap: list[_T]) -> _T: ...
diff --git a/mypy/typeshed/stdlib/_py_abc.pyi b/mypy/typeshed/stdlib/_py_abc.pyi
index ddf04364a238..cc45c6ad3814 100644
--- a/mypy/typeshed/stdlib/_py_abc.pyi
+++ b/mypy/typeshed/stdlib/_py_abc.pyi
@@ -1,4 +1,4 @@
-from _typeshed import Self
+import _typeshed
 from typing import Any, NewType, TypeVar
 
 _T = TypeVar("_T")
@@ -8,5 +8,7 @@ _CacheToken = NewType("_CacheToken", int)
 def get_cache_token() -> _CacheToken: ...
 
 class ABCMeta(type):
-    def __new__(__mcls: type[Self], __name: str, __bases: tuple[type[Any], ...], __namespace: dict[str, Any]) -> Self: ...
+    def __new__(
+        __mcls: type[_typeshed.Self], __name: str, __bases: tuple[type[Any], ...], __namespace: dict[str, Any]
+    ) -> _typeshed.Self: ...
     def register(cls, subclass: type[_T]) -> type[_T]: ...
diff --git a/mypy/typeshed/stdlib/_typeshed/__init__.pyi b/mypy/typeshed/stdlib/_typeshed/__init__.pyi
index 68ac2a9b1900..d0c6b3ab1173 100644
--- a/mypy/typeshed/stdlib/_typeshed/__init__.pyi
+++ b/mypy/typeshed/stdlib/_typeshed/__init__.pyi
@@ -8,9 +8,10 @@ import mmap
 import pickle
 import sys
 from collections.abc import Awaitable, Callable, Iterable, Set as AbstractSet
+from dataclasses import Field
 from os import PathLike
 from types import FrameType, TracebackType
-from typing import Any, AnyStr, Generic, Protocol, TypeVar, Union
+from typing import Any, AnyStr, ClassVar, Generic, Protocol, TypeVar
 from typing_extensions import Final, Literal, LiteralString, TypeAlias, final
 
 _KT = TypeVar("_KT")
@@ -264,7 +265,7 @@ IndexableBuffer: TypeAlias = bytes | bytearray | memoryview | array.array[Any] |
 #     def __buffer__(self, __flags: int) -> memoryview: ...
 
 ExcInfo: TypeAlias = tuple[type[BaseException], BaseException, TracebackType]
-OptExcInfo: TypeAlias = Union[ExcInfo, tuple[None, None, None]]
+OptExcInfo: TypeAlias = ExcInfo | tuple[None, None, None]
 
 # stable
 if sys.version_info >= (3, 10):
@@ -304,3 +305,10 @@ ProfileFunction: TypeAlias = Callable[[FrameType, str, Any], object]
 
 # Objects suitable to be passed to sys.settrace, threading.settrace, and similar
 TraceFunction: TypeAlias = Callable[[FrameType, str, Any], TraceFunction | None]
+
+# experimental
+# Might not work as expected for pyright, see
+#   https://github.com/python/typeshed/pull/9362
+#   https://github.com/microsoft/pyright/issues/4339
+class DataclassInstance(Protocol):
+    __dataclass_fields__: ClassVar[dict[str, Field[Any]]]
diff --git a/mypy/typeshed/stdlib/_weakref.pyi b/mypy/typeshed/stdlib/_weakref.pyi
index df462ad859c7..2a43de3ffd6b 100644
--- a/mypy/typeshed/stdlib/_weakref.pyi
+++ b/mypy/typeshed/stdlib/_weakref.pyi
@@ -1,8 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Callable
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import final
+from typing_extensions import Self, final
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -21,7 +20,7 @@ class ProxyType(Generic[_T]):  # "weakproxy"
 
 class ReferenceType(Generic[_T]):
     __callback__: Callable[[ReferenceType[_T]], Any]
-    def __new__(cls: type[Self], o: _T, callback: Callable[[ReferenceType[_T]], Any] | None = ...) -> Self: ...
+    def __new__(cls, o: _T, callback: Callable[[ReferenceType[_T]], Any] | None = ...) -> Self: ...
     def __call__(self) -> _T | None: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
diff --git a/mypy/typeshed/stdlib/_weakrefset.pyi b/mypy/typeshed/stdlib/_weakrefset.pyi
index fdf26641bbeb..d73d79155329 100644
--- a/mypy/typeshed/stdlib/_weakrefset.pyi
+++ b/mypy/typeshed/stdlib/_weakrefset.pyi
@@ -1,7 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Iterable, Iterator, MutableSet
 from typing import Any, Generic, TypeVar, overload
+from typing_extensions import Self
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -18,21 +18,21 @@ class WeakSet(MutableSet[_T], Generic[_T]):
     def __init__(self, data: Iterable[_T]) -> None: ...
     def add(self, item: _T) -> None: ...
     def discard(self, item: _T) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def remove(self, item: _T) -> None: ...
     def update(self, other: Iterable[_T]) -> None: ...
     def __contains__(self, item: object) -> bool: ...
     def __len__(self) -> int: ...
     def __iter__(self) -> Iterator[_T]: ...
-    def __ior__(self: Self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
-    def difference(self: Self, other: Iterable[_T]) -> Self: ...
-    def __sub__(self: Self, other: Iterable[Any]) -> Self: ...
+    def __ior__(self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
+    def difference(self, other: Iterable[_T]) -> Self: ...
+    def __sub__(self, other: Iterable[Any]) -> Self: ...
     def difference_update(self, other: Iterable[Any]) -> None: ...
-    def __isub__(self: Self, other: Iterable[Any]) -> Self: ...
-    def intersection(self: Self, other: Iterable[_T]) -> Self: ...
-    def __and__(self: Self, other: Iterable[Any]) -> Self: ...
+    def __isub__(self, other: Iterable[Any]) -> Self: ...
+    def intersection(self, other: Iterable[_T]) -> Self: ...
+    def __and__(self, other: Iterable[Any]) -> Self: ...
     def intersection_update(self, other: Iterable[Any]) -> None: ...
-    def __iand__(self: Self, other: Iterable[Any]) -> Self: ...
+    def __iand__(self, other: Iterable[Any]) -> Self: ...
     def issubset(self, other: Iterable[_T]) -> bool: ...
     def __le__(self, other: Iterable[_T]) -> bool: ...
     def __lt__(self, other: Iterable[_T]) -> bool: ...
@@ -43,7 +43,7 @@ class WeakSet(MutableSet[_T], Generic[_T]):
     def symmetric_difference(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
     def __xor__(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
     def symmetric_difference_update(self, other: Iterable[_T]) -> None: ...
-    def __ixor__(self: Self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
+    def __ixor__(self, other: Iterable[_T]) -> Self: ...  # type: ignore[override,misc]
     def union(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
     def __or__(self, other: Iterable[_S]) -> WeakSet[_S | _T]: ...
     def isdisjoint(self, other: Iterable[_T]) -> bool: ...
diff --git a/mypy/typeshed/stdlib/_winapi.pyi b/mypy/typeshed/stdlib/_winapi.pyi
index 5e0087e29934..e21402b801c5 100644
--- a/mypy/typeshed/stdlib/_winapi.pyi
+++ b/mypy/typeshed/stdlib/_winapi.pyi
@@ -5,13 +5,15 @@ from typing import Any, NoReturn, overload
 from typing_extensions import Literal, final
 
 if sys.platform == "win32":
-    ABOVE_NORMAL_PRIORITY_CLASS: Literal[32768]
-    BELOW_NORMAL_PRIORITY_CLASS: Literal[16384]
-    CREATE_BREAKAWAY_FROM_JOB: Literal[16777216]
-    CREATE_DEFAULT_ERROR_MODE: Literal[67108864]
-    CREATE_NO_WINDOW: Literal[134217728]
-    CREATE_NEW_CONSOLE: Literal[16]
-    CREATE_NEW_PROCESS_GROUP: Literal[512]
+    ABOVE_NORMAL_PRIORITY_CLASS: Literal[0x8000]
+    BELOW_NORMAL_PRIORITY_CLASS: Literal[0x4000]
+
+    CREATE_BREAKAWAY_FROM_JOB: Literal[0x1000000]
+    CREATE_DEFAULT_ERROR_MODE: Literal[0x4000000]
+    CREATE_NO_WINDOW: Literal[0x8000000]
+    CREATE_NEW_CONSOLE: Literal[0x10]
+    CREATE_NEW_PROCESS_GROUP: Literal[0x200]
+
     DETACHED_PROCESS: Literal[8]
     DUPLICATE_CLOSE_SOURCE: Literal[1]
     DUPLICATE_SAME_ACCESS: Literal[2]
@@ -28,40 +30,43 @@ if sys.platform == "win32":
     ERROR_PIPE_CONNECTED: Literal[535]
     ERROR_SEM_TIMEOUT: Literal[121]
 
-    FILE_FLAG_FIRST_PIPE_INSTANCE: Literal[524288]
-    FILE_FLAG_OVERLAPPED: Literal[1073741824]
+    FILE_FLAG_FIRST_PIPE_INSTANCE: Literal[0x80000]
+    FILE_FLAG_OVERLAPPED: Literal[0x40000000]
+
     FILE_GENERIC_READ: Literal[1179785]
     FILE_GENERIC_WRITE: Literal[1179926]
+
     if sys.version_info >= (3, 8):
         FILE_MAP_ALL_ACCESS: Literal[983071]
         FILE_MAP_COPY: Literal[1]
         FILE_MAP_EXECUTE: Literal[32]
         FILE_MAP_READ: Literal[4]
         FILE_MAP_WRITE: Literal[2]
+
     FILE_TYPE_CHAR: Literal[2]
     FILE_TYPE_DISK: Literal[1]
     FILE_TYPE_PIPE: Literal[3]
     FILE_TYPE_REMOTE: Literal[32768]
     FILE_TYPE_UNKNOWN: Literal[0]
 
-    GENERIC_READ: Literal[2147483648]
-    GENERIC_WRITE: Literal[1073741824]
-    HIGH_PRIORITY_CLASS: Literal[128]
-    INFINITE: Literal[4294967295]
+    GENERIC_READ: Literal[0x80000000]
+    GENERIC_WRITE: Literal[0x40000000]
+    HIGH_PRIORITY_CLASS: Literal[0x80]
+    INFINITE: Literal[0xFFFFFFFF]
     if sys.version_info >= (3, 8):
-        INVALID_HANDLE_VALUE: int  # very large number
-    IDLE_PRIORITY_CLASS: Literal[64]
-    NORMAL_PRIORITY_CLASS: Literal[32]
-    REALTIME_PRIORITY_CLASS: Literal[256]
-    NMPWAIT_WAIT_FOREVER: Literal[4294967295]
+        INVALID_HANDLE_VALUE: Literal[0xFFFFFFFFFFFFFFFF]
+    IDLE_PRIORITY_CLASS: Literal[0x40]
+    NORMAL_PRIORITY_CLASS: Literal[0x20]
+    REALTIME_PRIORITY_CLASS: Literal[0x100]
+    NMPWAIT_WAIT_FOREVER: Literal[0xFFFFFFFF]
 
     if sys.version_info >= (3, 8):
-        MEM_COMMIT: Literal[4096]
-        MEM_FREE: Literal[65536]
-        MEM_IMAGE: Literal[16777216]
-        MEM_MAPPED: Literal[262144]
-        MEM_PRIVATE: Literal[131072]
-        MEM_RESERVE: Literal[8192]
+        MEM_COMMIT: Literal[0x1000]
+        MEM_FREE: Literal[0x10000]
+        MEM_IMAGE: Literal[0x1000000]
+        MEM_MAPPED: Literal[0x40000]
+        MEM_PRIVATE: Literal[0x20000]
+        MEM_RESERVE: Literal[0x2000]
 
     NULL: Literal[0]
     OPEN_EXISTING: Literal[3]
@@ -72,37 +77,42 @@ if sys.platform == "win32":
     PIPE_TYPE_MESSAGE: Literal[4]
     PIPE_UNLIMITED_INSTANCES: Literal[255]
     PIPE_WAIT: Literal[0]
+
     if sys.version_info >= (3, 8):
-        PAGE_EXECUTE: Literal[16]
-        PAGE_EXECUTE_READ: Literal[32]
-        PAGE_EXECUTE_READWRITE: Literal[64]
-        PAGE_EXECUTE_WRITECOPY: Literal[128]
-        PAGE_GUARD: Literal[256]
-        PAGE_NOACCESS: Literal[1]
-        PAGE_NOCACHE: Literal[512]
-        PAGE_READONLY: Literal[2]
-        PAGE_READWRITE: Literal[4]
-        PAGE_WRITECOMBINE: Literal[1024]
-        PAGE_WRITECOPY: Literal[8]
-
-    PROCESS_ALL_ACCESS: Literal[2097151]
-    PROCESS_DUP_HANDLE: Literal[64]
+        PAGE_EXECUTE: Literal[0x10]
+        PAGE_EXECUTE_READ: Literal[0x20]
+        PAGE_EXECUTE_READWRITE: Literal[0x40]
+        PAGE_EXECUTE_WRITECOPY: Literal[0x80]
+        PAGE_GUARD: Literal[0x100]
+        PAGE_NOACCESS: Literal[0x1]
+        PAGE_NOCACHE: Literal[0x200]
+        PAGE_READONLY: Literal[0x2]
+        PAGE_READWRITE: Literal[0x4]
+        PAGE_WRITECOMBINE: Literal[0x400]
+        PAGE_WRITECOPY: Literal[0x8]
+
+    PROCESS_ALL_ACCESS: Literal[0x1FFFFF]
+    PROCESS_DUP_HANDLE: Literal[0x40]
+
     if sys.version_info >= (3, 8):
-        SEC_COMMIT: Literal[134217728]
-        SEC_IMAGE: Literal[16777216]
-        SEC_LARGE_PAGES: Literal[2147483648]
-        SEC_NOCACHE: Literal[268435456]
-        SEC_RESERVE: Literal[67108864]
-        SEC_WRITECOMBINE: Literal[1073741824]
-    STARTF_USESHOWWINDOW: Literal[1]
-    STARTF_USESTDHANDLES: Literal[256]
-    STD_ERROR_HANDLE: Literal[4294967284]
-    STD_INPUT_HANDLE: Literal[4294967286]
-    STD_OUTPUT_HANDLE: Literal[4294967285]
+        SEC_COMMIT: Literal[0x8000000]
+        SEC_IMAGE: Literal[0x1000000]
+        SEC_LARGE_PAGES: Literal[0x80000000]
+        SEC_NOCACHE: Literal[0x10000000]
+        SEC_RESERVE: Literal[0x4000000]
+        SEC_WRITECOMBINE: Literal[0x40000000]
+
+    STARTF_USESHOWWINDOW: Literal[0x1]
+    STARTF_USESTDHANDLES: Literal[0x100]
+
+    STD_ERROR_HANDLE: Literal[0xFFFFFFF4]
+    STD_OUTPUT_HANDLE: Literal[0xFFFFFFF5]
+    STD_INPUT_HANDLE: Literal[0xFFFFFFF6]
+
     STILL_ACTIVE: Literal[259]
     SW_HIDE: Literal[0]
     if sys.version_info >= (3, 8):
-        SYNCHRONIZE: Literal[1048576]
+        SYNCHRONIZE: Literal[0x100000]
     WAIT_ABANDONED_0: Literal[128]
     WAIT_OBJECT_0: Literal[0]
     WAIT_TIMEOUT: Literal[258]
@@ -196,7 +206,7 @@ if sys.platform == "win32":
         __named_pipe: int, __mode: int | None, __max_collection_count: int | None, __collect_data_timeout: int | None
     ) -> None: ...
     def TerminateProcess(__handle: int, __exit_code: int) -> None: ...
-    def WaitForMultipleObjects(__handle_seq: Sequence[int], __wait_flag: bool, __milliseconds: int = 4294967295) -> int: ...
+    def WaitForMultipleObjects(__handle_seq: Sequence[int], __wait_flag: bool, __milliseconds: int = 0xFFFFFFFF) -> int: ...
     def WaitForSingleObject(__handle: int, __milliseconds: int) -> int: ...
     def WaitNamedPipe(__name: str, __timeout: int) -> None: ...
     @overload
diff --git a/mypy/typeshed/stdlib/abc.pyi b/mypy/typeshed/stdlib/abc.pyi
index 44a5b2289832..068dab4752be 100644
--- a/mypy/typeshed/stdlib/abc.pyi
+++ b/mypy/typeshed/stdlib/abc.pyi
@@ -1,5 +1,6 @@
+import _typeshed
 import sys
-from _typeshed import Self, SupportsWrite
+from _typeshed import SupportsWrite
 from collections.abc import Callable
 from typing import Any, Generic, TypeVar
 from typing_extensions import Literal
@@ -13,10 +14,12 @@ class ABCMeta(type):
     __abstractmethods__: frozenset[str]
     if sys.version_info >= (3, 11):
         def __new__(
-            __mcls: type[Self], __name: str, __bases: tuple[type, ...], __namespace: dict[str, Any], **kwargs: Any
-        ) -> Self: ...
+            __mcls: type[_typeshed.Self], __name: str, __bases: tuple[type, ...], __namespace: dict[str, Any], **kwargs: Any
+        ) -> _typeshed.Self: ...
     else:
-        def __new__(mcls: type[Self], name: str, bases: tuple[type, ...], namespace: dict[str, Any], **kwargs: Any) -> Self: ...
+        def __new__(
+            mcls: type[_typeshed.Self], name: str, bases: tuple[type, ...], namespace: dict[str, Any], **kwargs: Any
+        ) -> _typeshed.Self: ...
 
     def __instancecheck__(cls: ABCMeta, instance: Any) -> bool: ...
     def __subclasscheck__(cls: ABCMeta, subclass: type) -> bool: ...
diff --git a/mypy/typeshed/stdlib/aifc.pyi b/mypy/typeshed/stdlib/aifc.pyi
index ad126d6cdbef..ab0c18ed6623 100644
--- a/mypy/typeshed/stdlib/aifc.pyi
+++ b/mypy/typeshed/stdlib/aifc.pyi
@@ -1,8 +1,7 @@
 import sys
-from _typeshed import Self
 from types import TracebackType
 from typing import IO, Any, NamedTuple, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     __all__ = ["Error", "open"]
@@ -24,7 +23,7 @@ _Marker: TypeAlias = tuple[int, int, bytes]
 
 class Aifc_read:
     def __init__(self, f: _File) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
@@ -48,7 +47,7 @@ class Aifc_read:
 class Aifc_write:
     def __init__(self, f: _File) -> None: ...
     def __del__(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/array.pyi b/mypy/typeshed/stdlib/array.pyi
index 25c389c47e8e..827bbb97897f 100644
--- a/mypy/typeshed/stdlib/array.pyi
+++ b/mypy/typeshed/stdlib/array.pyi
@@ -1,10 +1,10 @@
 import sys
-from _typeshed import ReadableBuffer, Self, SupportsRead, SupportsWrite
+from _typeshed import ReadableBuffer, SupportsRead, SupportsWrite
 from collections.abc import Iterable
 
 # pytype crashes if array inherits from collections.abc.MutableSequence instead of typing.MutableSequence
 from typing import Any, Generic, MutableSequence, TypeVar, overload  # noqa: Y022
-from typing_extensions import Literal, SupportsIndex, TypeAlias
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias
 
 _IntTypeCode: TypeAlias = Literal["b", "B", "h", "H", "i", "I", "l", "L", "q", "Q"]
 _FloatTypeCode: TypeAlias = Literal["f", "d"]
@@ -72,8 +72,8 @@ class array(MutableSequence[_T], Generic[_T]):
     def __add__(self, __x: array[_T]) -> array[_T]: ...
     def __ge__(self, __other: array[_T]) -> bool: ...
     def __gt__(self, __other: array[_T]) -> bool: ...
-    def __iadd__(self: Self, __x: array[_T]) -> Self: ...  # type: ignore[override]
-    def __imul__(self: Self, __n: int) -> Self: ...
+    def __iadd__(self, __x: array[_T]) -> Self: ...  # type: ignore[override]
+    def __imul__(self, __n: int) -> Self: ...
     def __le__(self, __other: array[_T]) -> bool: ...
     def __lt__(self, __other: array[_T]) -> bool: ...
     def __mul__(self, __n: int) -> array[_T]: ...
diff --git a/mypy/typeshed/stdlib/asyncio/events.pyi b/mypy/typeshed/stdlib/asyncio/events.pyi
index b2292801ee0d..f97afe873c9f 100644
--- a/mypy/typeshed/stdlib/asyncio/events.pyi
+++ b/mypy/typeshed/stdlib/asyncio/events.pyi
@@ -1,12 +1,12 @@
 import ssl
 import sys
-from _typeshed import FileDescriptorLike, ReadableBuffer, Self, StrPath, Unused, WriteableBuffer
+from _typeshed import FileDescriptorLike, ReadableBuffer, StrPath, Unused, WriteableBuffer
 from abc import ABCMeta, abstractmethod
 from collections.abc import Awaitable, Callable, Coroutine, Generator, Sequence
 from contextvars import Context
 from socket import AddressFamily, SocketKind, _Address, _RetAddress, socket
 from typing import IO, Any, Protocol, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 from .base_events import Server
 from .futures import Future
@@ -95,7 +95,7 @@ class TimerHandle(Handle):
 class AbstractServer:
     @abstractmethod
     def close(self) -> None: ...
-    async def __aenter__(self: Self) -> Self: ...
+    async def __aenter__(self) -> Self: ...
     async def __aexit__(self, *exc: Unused) -> None: ...
     @abstractmethod
     def get_loop(self) -> AbstractEventLoop: ...
@@ -524,11 +524,11 @@ class AbstractEventLoop:
         stdin: int | IO[Any] | None = -1,
         stdout: int | IO[Any] | None = -1,
         stderr: int | IO[Any] | None = -1,
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[False, None] = ...,
         **kwargs: Any,
     ) -> tuple[SubprocessTransport, _ProtocolT]: ...
@@ -541,11 +541,11 @@ class AbstractEventLoop:
         stdin: int | IO[Any] | None = -1,
         stdout: int | IO[Any] | None = -1,
         stderr: int | IO[Any] | None = -1,
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[False] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[False] = False,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         **kwargs: Any,
     ) -> tuple[SubprocessTransport, _ProtocolT]: ...
     @abstractmethod
diff --git a/mypy/typeshed/stdlib/asyncio/futures.pyi b/mypy/typeshed/stdlib/asyncio/futures.pyi
index f325272d2403..79209f5ed4fb 100644
--- a/mypy/typeshed/stdlib/asyncio/futures.pyi
+++ b/mypy/typeshed/stdlib/asyncio/futures.pyi
@@ -1,9 +1,8 @@
 import sys
-from _typeshed import Self
 from collections.abc import Awaitable, Callable, Generator, Iterable
 from concurrent.futures._base import Error, Future as _ConcurrentFuture
 from typing import Any, TypeVar
-from typing_extensions import Literal, TypeGuard
+from typing_extensions import Literal, Self, TypeGuard
 
 from .events import AbstractEventLoop
 
@@ -43,8 +42,8 @@ class Future(Awaitable[_T], Iterable[_T]):
     def __del__(self) -> None: ...
     def get_loop(self) -> AbstractEventLoop: ...
     @property
-    def _callbacks(self: Self) -> list[tuple[Callable[[Self], Any], Context]]: ...
-    def add_done_callback(self: Self, __fn: Callable[[Self], object], *, context: Context | None = None) -> None: ...
+    def _callbacks(self) -> list[tuple[Callable[[Self], Any], Context]]: ...
+    def add_done_callback(self, __fn: Callable[[Self], object], *, context: Context | None = None) -> None: ...
     if sys.version_info >= (3, 9):
         def cancel(self, msg: Any | None = None) -> bool: ...
     else:
@@ -54,7 +53,7 @@ class Future(Awaitable[_T], Iterable[_T]):
     def done(self) -> bool: ...
     def result(self) -> _T: ...
     def exception(self) -> BaseException | None: ...
-    def remove_done_callback(self: Self, __fn: Callable[[Self], object]) -> int: ...
+    def remove_done_callback(self, __fn: Callable[[Self], object]) -> int: ...
     def set_result(self, __result: _T) -> None: ...
     def set_exception(self, __exception: type | BaseException) -> None: ...
     def __iter__(self) -> Generator[Any, None, _T]: ...
diff --git a/mypy/typeshed/stdlib/asyncio/locks.pyi b/mypy/typeshed/stdlib/asyncio/locks.pyi
index 87bcaa2110db..ab4e63ab59b1 100644
--- a/mypy/typeshed/stdlib/asyncio/locks.pyi
+++ b/mypy/typeshed/stdlib/asyncio/locks.pyi
@@ -1,11 +1,11 @@
 import enum
 import sys
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from collections import deque
 from collections.abc import Callable, Generator
 from types import TracebackType
 from typing import Any, TypeVar
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 from .events import AbstractEventLoop
 from .futures import Future
@@ -103,7 +103,7 @@ if sys.version_info >= (3, 11):
 
     class Barrier(_LoopBoundMixin):
         def __init__(self, parties: int) -> None: ...
-        async def __aenter__(self: Self) -> Self: ...
+        async def __aenter__(self) -> Self: ...
         async def __aexit__(self, *args: Unused) -> None: ...
         async def wait(self) -> int: ...
         async def abort(self) -> None: ...
diff --git a/mypy/typeshed/stdlib/asyncio/runners.pyi b/mypy/typeshed/stdlib/asyncio/runners.pyi
index 484f9eb831a1..847072b633ac 100644
--- a/mypy/typeshed/stdlib/asyncio/runners.pyi
+++ b/mypy/typeshed/stdlib/asyncio/runners.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from collections.abc import Callable, Coroutine
 from contextvars import Context
 from typing import Any, TypeVar
-from typing_extensions import final
+from typing_extensions import Self, final
 
 from .events import AbstractEventLoop
 
@@ -17,7 +17,7 @@ if sys.version_info >= (3, 11):
     @final
     class Runner:
         def __init__(self, *, debug: bool | None = None, loop_factory: Callable[[], AbstractEventLoop] | None = None) -> None: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, exc_type: Unused, exc_val: Unused, exc_tb: Unused) -> None: ...
         def close(self) -> None: ...
         def get_loop(self) -> AbstractEventLoop: ...
diff --git a/mypy/typeshed/stdlib/asyncio/streams.pyi b/mypy/typeshed/stdlib/asyncio/streams.pyi
index 2468f482291c..f30c57305d93 100644
--- a/mypy/typeshed/stdlib/asyncio/streams.pyi
+++ b/mypy/typeshed/stdlib/asyncio/streams.pyi
@@ -1,9 +1,9 @@
 import ssl
 import sys
-from _typeshed import Self, StrPath
+from _typeshed import StrPath
 from collections.abc import AsyncIterator, Awaitable, Callable, Iterable, Sequence
 from typing import Any
-from typing_extensions import SupportsIndex, TypeAlias
+from typing_extensions import Self, SupportsIndex, TypeAlias
 
 from . import events, protocols, transports
 from .base_events import Server
@@ -166,5 +166,5 @@ class StreamReader(AsyncIterator[bytes]):
     async def readuntil(self, separator: bytes | bytearray | memoryview = b"\n") -> bytes: ...
     async def read(self, n: int = -1) -> bytes: ...
     async def readexactly(self, n: int) -> bytes: ...
-    def __aiter__(self: Self) -> Self: ...
+    def __aiter__(self) -> Self: ...
     async def __anext__(self) -> bytes: ...
diff --git a/mypy/typeshed/stdlib/asyncio/subprocess.pyi b/mypy/typeshed/stdlib/asyncio/subprocess.pyi
index b112a9d80a32..10a414f24537 100644
--- a/mypy/typeshed/stdlib/asyncio/subprocess.pyi
+++ b/mypy/typeshed/stdlib/asyncio/subprocess.pyi
@@ -49,11 +49,11 @@ if sys.version_info >= (3, 11):
         limit: int = 65536,
         *,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[False, None] = ...,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         executable: StrOrBytesPath | None = ...,
@@ -81,11 +81,11 @@ if sys.version_info >= (3, 11):
         stderr: int | IO[Any] | None = None,
         limit: int = 65536,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         text: bool | None = ...,
         executable: StrOrBytesPath | None = ...,
@@ -115,11 +115,11 @@ elif sys.version_info >= (3, 10):
         limit: int = 65536,
         *,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[False, None] = ...,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         executable: StrOrBytesPath | None = ...,
@@ -146,11 +146,11 @@ elif sys.version_info >= (3, 10):
         stderr: int | IO[Any] | None = None,
         limit: int = 65536,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         text: bool | None = ...,
         executable: StrOrBytesPath | None = ...,
@@ -180,11 +180,11 @@ else:  # >= 3.9
         limit: int = 65536,
         *,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[False, None] = ...,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         executable: StrOrBytesPath | None = ...,
@@ -211,11 +211,11 @@ else:  # >= 3.9
         loop: events.AbstractEventLoop | None = None,
         limit: int = 65536,
         # These parameters are forced to these values by BaseEventLoop.subprocess_shell
-        universal_newlines: Literal[False] = ...,
-        shell: Literal[True] = ...,
-        bufsize: Literal[0] = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        universal_newlines: Literal[False] = False,
+        shell: Literal[True] = True,
+        bufsize: Literal[0] = 0,
+        encoding: None = None,
+        errors: None = None,
         # These parameters are taken by subprocess.Popen, which this ultimately delegates to
         text: bool | None = ...,
         executable: StrOrBytesPath | None = ...,
diff --git a/mypy/typeshed/stdlib/asyncio/taskgroups.pyi b/mypy/typeshed/stdlib/asyncio/taskgroups.pyi
index 9e6c6e047368..8daa96f1ede0 100644
--- a/mypy/typeshed/stdlib/asyncio/taskgroups.pyi
+++ b/mypy/typeshed/stdlib/asyncio/taskgroups.pyi
@@ -1,10 +1,10 @@
 # This only exists in 3.11+. See VERSIONS.
 
-from _typeshed import Self
 from collections.abc import Coroutine, Generator
 from contextvars import Context
 from types import TracebackType
 from typing import Any, TypeVar
+from typing_extensions import Self
 
 from .tasks import Task
 
@@ -13,7 +13,7 @@ __all__ = ["TaskGroup"]
 _T = TypeVar("_T")
 
 class TaskGroup:
-    async def __aenter__(self: Self) -> Self: ...
+    async def __aenter__(self) -> Self: ...
     async def __aexit__(self, et: type[BaseException] | None, exc: BaseException | None, tb: TracebackType | None) -> None: ...
     def create_task(
         self, coro: Generator[Any, None, _T] | Coroutine[Any, Any, _T], *, name: str | None = None, context: Context | None = None
diff --git a/mypy/typeshed/stdlib/asyncio/timeouts.pyi b/mypy/typeshed/stdlib/asyncio/timeouts.pyi
index be516b5851d1..2d31b777b77d 100644
--- a/mypy/typeshed/stdlib/asyncio/timeouts.pyi
+++ b/mypy/typeshed/stdlib/asyncio/timeouts.pyi
@@ -1,6 +1,5 @@
-from _typeshed import Self
 from types import TracebackType
-from typing_extensions import final
+from typing_extensions import Self, final
 
 __all__ = ("Timeout", "timeout", "timeout_at")
 
@@ -10,7 +9,7 @@ class Timeout:
     def when(self) -> float | None: ...
     def reschedule(self, when: float | None) -> None: ...
     def expired(self) -> bool: ...
-    async def __aenter__(self: Self) -> Self: ...
+    async def __aenter__(self) -> Self: ...
     async def __aexit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/asyncio/unix_events.pyi b/mypy/typeshed/stdlib/asyncio/unix_events.pyi
index 5e2b05f57ef1..e28d64b5287b 100644
--- a/mypy/typeshed/stdlib/asyncio/unix_events.pyi
+++ b/mypy/typeshed/stdlib/asyncio/unix_events.pyi
@@ -1,10 +1,9 @@
 import sys
 import types
-from _typeshed import Self
 from abc import ABCMeta, abstractmethod
 from collections.abc import Callable
 from typing import Any
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 from .events import AbstractEventLoop, BaseDefaultEventLoopPolicy
 from .selector_events import BaseSelectorEventLoop
@@ -22,7 +21,7 @@ class AbstractChildWatcher:
     @abstractmethod
     def close(self) -> None: ...
     @abstractmethod
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     @abstractmethod
     def __exit__(self, typ: type[BaseException] | None, exc: BaseException | None, tb: types.TracebackType | None) -> None: ...
     if sys.version_info >= (3, 8):
@@ -64,13 +63,13 @@ if sys.platform != "win32":
         def attach_loop(self, loop: AbstractEventLoop | None) -> None: ...
 
     class SafeChildWatcher(BaseChildWatcher):
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, a: type[BaseException] | None, b: BaseException | None, c: types.TracebackType | None) -> None: ...
         def add_child_handler(self, pid: int, callback: Callable[..., object], *args: Any) -> None: ...
         def remove_child_handler(self, pid: int) -> bool: ...
 
     class FastChildWatcher(BaseChildWatcher):
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, a: type[BaseException] | None, b: BaseException | None, c: types.TracebackType | None) -> None: ...
         def add_child_handler(self, pid: int, callback: Callable[..., object], *args: Any) -> None: ...
         def remove_child_handler(self, pid: int) -> bool: ...
@@ -95,7 +94,7 @@ if sys.platform != "win32":
         class MultiLoopChildWatcher(AbstractChildWatcher):
             def is_active(self) -> bool: ...
             def close(self) -> None: ...
-            def __enter__(self: Self) -> Self: ...
+            def __enter__(self) -> Self: ...
             def __exit__(
                 self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: types.TracebackType | None
             ) -> None: ...
@@ -106,7 +105,7 @@ if sys.platform != "win32":
         class ThreadedChildWatcher(AbstractChildWatcher):
             def is_active(self) -> Literal[True]: ...
             def close(self) -> None: ...
-            def __enter__(self: Self) -> Self: ...
+            def __enter__(self) -> Self: ...
             def __exit__(
                 self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: types.TracebackType | None
             ) -> None: ...
@@ -117,7 +116,7 @@ if sys.platform != "win32":
 
     if sys.version_info >= (3, 9):
         class PidfdChildWatcher(AbstractChildWatcher):
-            def __enter__(self: Self) -> Self: ...
+            def __enter__(self) -> Self: ...
             def __exit__(
                 self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: types.TracebackType | None
             ) -> None: ...
diff --git a/mypy/typeshed/stdlib/asyncio/windows_utils.pyi b/mypy/typeshed/stdlib/asyncio/windows_utils.pyi
index 6ac4e0d89aa4..f3a82e2b8462 100644
--- a/mypy/typeshed/stdlib/asyncio/windows_utils.pyi
+++ b/mypy/typeshed/stdlib/asyncio/windows_utils.pyi
@@ -1,10 +1,9 @@
 import subprocess
 import sys
-from _typeshed import Self
 from collections.abc import Callable
 from types import TracebackType
 from typing import Any, AnyStr, Protocol
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 if sys.platform == "win32":
     __all__ = ("pipe", "Popen", "PIPE", "PipeHandle")
@@ -25,7 +24,7 @@ if sys.platform == "win32":
         else:
             def __del__(self) -> None: ...
 
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
         @property
         def handle(self) -> int: ...
@@ -41,7 +40,7 @@ if sys.platform == "win32":
         # subprocess.Popen takes other positional-or-keyword arguments before
         # stdin.
         def __new__(
-            cls: type[Self],
+            cls,
             args: subprocess._CMD,
             stdin: subprocess._FILE | None = ...,
             stdout: subprocess._FILE | None = ...,
diff --git a/mypy/typeshed/stdlib/builtins.pyi b/mypy/typeshed/stdlib/builtins.pyi
index 9f45a937764b..7b8e25084c91 100644
--- a/mypy/typeshed/stdlib/builtins.pyi
+++ b/mypy/typeshed/stdlib/builtins.pyi
@@ -1,4 +1,5 @@
 import _ast
+import _typeshed
 import sys
 import types
 from _collections_abc import dict_items, dict_keys, dict_values
@@ -11,7 +12,6 @@ from _typeshed import (
     OpenBinaryModeWriting,
     OpenTextMode,
     ReadableBuffer,
-    Self,
     SupportsAdd,
     SupportsAiter,
     SupportsAnext,
@@ -54,7 +54,7 @@ from typing import (  # noqa: Y022
     overload,
     type_check_only,
 )
-from typing_extensions import Literal, SupportsIndex, TypeAlias, TypeGuard, final
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias, TypeGuard, final
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -82,12 +82,12 @@ class object:
     __module__: str
     __annotations__: dict[str, Any]
     @property
-    def __class__(self: Self) -> type[Self]: ...
+    def __class__(self) -> type[Self]: ...
     # Ignore errors about type mismatch between property getter and setter
     @__class__.setter
     def __class__(self, __type: type[object]) -> None: ...  # noqa: F811
     def __init__(self) -> None: ...
-    def __new__(cls: type[Self]) -> Self: ...
+    def __new__(cls) -> Self: ...
     # N.B. `object.__setattr__` and `object.__delattr__` are heavily special-cased by type checkers.
     # Overriding them in subclasses has different semantics, even if the override has an identical signature.
     def __setattr__(self, __name: str, __value: Any) -> None: ...
@@ -168,9 +168,11 @@ class type:
     @overload
     def __new__(cls, __o: object) -> type: ...
     @overload
-    def __new__(cls: type[Self], __name: str, __bases: tuple[type, ...], __namespace: dict[str, Any], **kwds: Any) -> Self: ...
+    def __new__(
+        cls: type[_typeshed.Self], __name: str, __bases: tuple[type, ...], __namespace: dict[str, Any], **kwds: Any
+    ) -> _typeshed.Self: ...
     def __call__(self, *args: Any, **kwds: Any) -> Any: ...
-    def __subclasses__(self: Self) -> list[Self]: ...
+    def __subclasses__(self: _typeshed.Self) -> list[_typeshed.Self]: ...
     # Note: the documentation doesn't specify what the return type is, the standard
     # implementation seems to be returning a list.
     def mro(self) -> list[type]: ...
@@ -196,9 +198,9 @@ _LiteralInteger = _PositiveInteger | _NegativeInteger | Literal[0]  # noqa: Y026
 
 class int:
     @overload
-    def __new__(cls: type[Self], __x: str | ReadableBuffer | SupportsInt | SupportsIndex | SupportsTrunc = ...) -> Self: ...
+    def __new__(cls, __x: str | ReadableBuffer | SupportsInt | SupportsIndex | SupportsTrunc = ...) -> Self: ...
     @overload
-    def __new__(cls: type[Self], __x: str | bytes | bytearray, base: SupportsIndex) -> Self: ...
+    def __new__(cls, __x: str | bytes | bytearray, base: SupportsIndex) -> Self: ...
     if sys.version_info >= (3, 8):
         def as_integer_ratio(self) -> tuple[int, Literal[1]]: ...
 
@@ -221,7 +223,7 @@ class int:
         ) -> bytes: ...
         @classmethod
         def from_bytes(
-            cls: type[Self],
+            cls,
             bytes: Iterable[SupportsIndex] | SupportsBytes | ReadableBuffer,
             byteorder: Literal["little", "big"] = "big",
             *,
@@ -231,7 +233,7 @@ class int:
         def to_bytes(self, length: SupportsIndex, byteorder: Literal["little", "big"], *, signed: bool = False) -> bytes: ...
         @classmethod
         def from_bytes(
-            cls: type[Self],
+            cls,
             bytes: Iterable[SupportsIndex] | SupportsBytes | ReadableBuffer,
             byteorder: Literal["little", "big"],
             *,
@@ -257,13 +259,13 @@ class int:
     @overload
     def __pow__(self, __x: Literal[0], __modulo: None) -> Literal[1]: ...
     @overload
-    def __pow__(self, __x: _PositiveInteger, __modulo: None = ...) -> int: ...
+    def __pow__(self, __x: _PositiveInteger, __modulo: None = None) -> int: ...
     @overload
-    def __pow__(self, __x: _NegativeInteger, __modulo: None = ...) -> float: ...
+    def __pow__(self, __x: _NegativeInteger, __modulo: None = None) -> float: ...
     # positive x -> int; negative x -> float
     # return type must be Any as `int | float` causes too many false-positive errors
     @overload
-    def __pow__(self, __x: int, __modulo: None = ...) -> Any: ...
+    def __pow__(self, __x: int, __modulo: None = None) -> Any: ...
     @overload
     def __pow__(self, __x: int, __modulo: int) -> int: ...
     def __rpow__(self, __x: int, __mod: int | None = None) -> Any: ...
@@ -298,12 +300,12 @@ class int:
     def __index__(self) -> int: ...
 
 class float:
-    def __new__(cls: type[Self], __x: SupportsFloat | SupportsIndex | str | ReadableBuffer = ...) -> Self: ...
+    def __new__(cls, __x: SupportsFloat | SupportsIndex | str | ReadableBuffer = ...) -> Self: ...
     def as_integer_ratio(self) -> tuple[int, int]: ...
     def hex(self) -> str: ...
     def is_integer(self) -> bool: ...
     @classmethod
-    def fromhex(cls: type[Self], __s: str) -> Self: ...
+    def fromhex(cls, __s: str) -> Self: ...
     @property
     def real(self) -> float: ...
     @property
@@ -330,7 +332,7 @@ class float:
     def __rmod__(self, __x: float) -> float: ...
     def __rdivmod__(self, __x: float) -> tuple[float, float]: ...
     @overload
-    def __rpow__(self, __x: _PositiveInteger, __modulo: None = ...) -> float: ...
+    def __rpow__(self, __x: _PositiveInteger, __modulo: None = None) -> float: ...
     @overload
     def __rpow__(self, __x: _NegativeInteger, __mod: None = None) -> complex: ...
     # Returning `complex` for the general case gives too many false-positive errors.
@@ -364,19 +366,17 @@ class complex:
         # Python doesn't currently accept SupportsComplex for the second argument
         @overload
         def __new__(
-            cls: type[Self],
+            cls,
             real: complex | SupportsComplex | SupportsFloat | SupportsIndex = ...,
             imag: complex | SupportsFloat | SupportsIndex = ...,
         ) -> Self: ...
         @overload
-        def __new__(cls: type[Self], real: str | SupportsComplex | SupportsFloat | SupportsIndex | complex) -> Self: ...
+        def __new__(cls, real: str | SupportsComplex | SupportsFloat | SupportsIndex | complex) -> Self: ...
     else:
         @overload
-        def __new__(
-            cls: type[Self], real: complex | SupportsComplex | SupportsFloat = ..., imag: complex | SupportsFloat = ...
-        ) -> Self: ...
+        def __new__(cls, real: complex | SupportsComplex | SupportsFloat = ..., imag: complex | SupportsFloat = ...) -> Self: ...
         @overload
-        def __new__(cls: type[Self], real: str | SupportsComplex | SupportsFloat | complex) -> Self: ...
+        def __new__(cls, real: str | SupportsComplex | SupportsFloat | complex) -> Self: ...
 
     @property
     def real(self) -> float: ...
@@ -410,9 +410,9 @@ class _TranslateTable(Protocol):
 
 class str(Sequence[str]):
     @overload
-    def __new__(cls: type[Self], object: object = ...) -> Self: ...
+    def __new__(cls, object: object = ...) -> Self: ...
     @overload
-    def __new__(cls: type[Self], object: ReadableBuffer, encoding: str = ..., errors: str = ...) -> Self: ...
+    def __new__(cls, object: ReadableBuffer, encoding: str = ..., errors: str = ...) -> Self: ...
     def capitalize(self) -> str: ...  # type: ignore[misc]
     def casefold(self) -> str: ...  # type: ignore[misc]
     def center(self, __width: SupportsIndex, __fillchar: str = " ") -> str: ...  # type: ignore[misc]
@@ -497,11 +497,11 @@ class str(Sequence[str]):
 
 class bytes(ByteString):
     @overload
-    def __new__(cls: type[Self], __o: Iterable[SupportsIndex] | SupportsIndex | SupportsBytes | ReadableBuffer) -> Self: ...
+    def __new__(cls, __o: Iterable[SupportsIndex] | SupportsIndex | SupportsBytes | ReadableBuffer) -> Self: ...
     @overload
-    def __new__(cls: type[Self], __string: str, encoding: str, errors: str = ...) -> Self: ...
+    def __new__(cls, __string: str, encoding: str, errors: str = ...) -> Self: ...
     @overload
-    def __new__(cls: type[Self]) -> Self: ...
+    def __new__(cls) -> Self: ...
     def capitalize(self) -> bytes: ...
     def center(self, __width: SupportsIndex, __fillchar: bytes = b" ") -> bytes: ...
     def count(
@@ -573,7 +573,7 @@ class bytes(ByteString):
     def upper(self) -> bytes: ...
     def zfill(self, __width: SupportsIndex) -> bytes: ...
     @classmethod
-    def fromhex(cls: type[Self], __s: str) -> Self: ...
+    def fromhex(cls, __s: str) -> Self: ...
     @staticmethod
     def maketrans(__frm: ReadableBuffer, __to: ReadableBuffer) -> bytes: ...
     def __len__(self) -> int: ...
@@ -682,7 +682,7 @@ class bytearray(MutableSequence[int], ByteString):
     def upper(self) -> bytearray: ...
     def zfill(self, __width: SupportsIndex) -> bytearray: ...
     @classmethod
-    def fromhex(cls: type[Self], __string: str) -> Self: ...
+    def fromhex(cls, __string: str) -> Self: ...
     @staticmethod
     def maketrans(__frm: ReadableBuffer, __to: ReadableBuffer) -> bytes: ...
     def __len__(self) -> int: ...
@@ -699,10 +699,10 @@ class bytearray(MutableSequence[int], ByteString):
     def __delitem__(self, __i: SupportsIndex | slice) -> None: ...
     def __add__(self, __s: ReadableBuffer) -> bytearray: ...
     # The superclass wants us to accept Iterable[int], but that fails at runtime.
-    def __iadd__(self: Self, __s: ReadableBuffer) -> Self: ...  # type: ignore[override]
+    def __iadd__(self, __s: ReadableBuffer) -> Self: ...  # type: ignore[override]
     def __mul__(self, __n: SupportsIndex) -> bytearray: ...
     def __rmul__(self, __n: SupportsIndex) -> bytearray: ...
-    def __imul__(self: Self, __n: SupportsIndex) -> Self: ...
+    def __imul__(self, __n: SupportsIndex) -> Self: ...
     def __mod__(self, __value: Any) -> bytes: ...
     # Incompatible with Sequence.__contains__
     def __contains__(self, __o: SupportsIndex | ReadableBuffer) -> bool: ...  # type: ignore[override]
@@ -741,7 +741,7 @@ class memoryview(Sequence[int]):
     @property
     def nbytes(self) -> int: ...
     def __init__(self, obj: ReadableBuffer) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, __exc_type: type[BaseException] | None, __exc_val: BaseException | None, __exc_tb: TracebackType | None
     ) -> None: ...
@@ -776,7 +776,7 @@ class memoryview(Sequence[int]):
 
 @final
 class bool(int):
-    def __new__(cls: type[Self], __o: object = ...) -> Self: ...
+    def __new__(cls, __o: object = ...) -> Self: ...
     # The following overloads could be represented more elegantly with a TypeVar("_B", bool, int),
     # however mypy has a bug regarding TypeVar constraints (https://github.com/python/mypy/issues/11880).
     @overload
@@ -821,7 +821,7 @@ class slice:
     def indices(self, __len: SupportsIndex) -> tuple[int, int, int]: ...
 
 class tuple(Sequence[_T_co], Generic[_T_co]):
-    def __new__(cls: type[Self], __iterable: Iterable[_T_co] = ...) -> Self: ...
+    def __new__(cls, __iterable: Iterable[_T_co] = ...) -> Self: ...
     def __len__(self) -> int: ...
     def __contains__(self, __x: object) -> bool: ...
     @overload
@@ -909,10 +909,10 @@ class list(MutableSequence[_T], Generic[_T]):
     def __add__(self, __x: list[_T]) -> list[_T]: ...
     @overload
     def __add__(self, __x: list[_S]) -> list[_S | _T]: ...
-    def __iadd__(self: Self, __x: Iterable[_T]) -> Self: ...  # type: ignore[misc]
+    def __iadd__(self, __x: Iterable[_T]) -> Self: ...  # type: ignore[misc]
     def __mul__(self, __n: SupportsIndex) -> list[_T]: ...
     def __rmul__(self, __n: SupportsIndex) -> list[_T]: ...
-    def __imul__(self: Self, __n: SupportsIndex) -> Self: ...
+    def __imul__(self, __n: SupportsIndex) -> Self: ...
     def __contains__(self, __o: object) -> bool: ...
     def __reversed__(self) -> Iterator[_T]: ...
     def __gt__(self, __x: list[_T]) -> bool: ...
@@ -941,7 +941,7 @@ class dict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     # Cannot be Iterable[Sequence[_T]] or otherwise dict(["foo", "bar", "baz"]) is not an error
     @overload
     def __init__(self: dict[str, str], __iterable: Iterable[list[str]]) -> None: ...
-    def __new__(cls: type[Self], *args: Any, **kwargs: Any) -> Self: ...
+    def __new__(cls, *args: Any, **kwargs: Any) -> Self: ...
     def copy(self) -> dict[_KT, _VT]: ...
     def keys(self) -> dict_keys[_KT, _VT]: ...
     def values(self) -> dict_values[_KT, _VT]: ...
@@ -978,9 +978,9 @@ class dict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
         def __ror__(self, __value: Mapping[_T1, _T2]) -> dict[_KT | _T1, _VT | _T2]: ...
         # dict.__ior__ should be kept roughly in line with MutableMapping.update()
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, __value: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
+        def __ior__(self, __value: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
         @overload
-        def __ior__(self: Self, __value: Iterable[tuple[_KT, _VT]]) -> Self: ...
+        def __ior__(self, __value: Iterable[tuple[_KT, _VT]]) -> Self: ...
 
 class set(MutableSet[_T], Generic[_T]):
     @overload
@@ -1006,13 +1006,13 @@ class set(MutableSet[_T], Generic[_T]):
     def __contains__(self, __o: object) -> bool: ...
     def __iter__(self) -> Iterator[_T]: ...
     def __and__(self, __s: AbstractSet[object]) -> set[_T]: ...
-    def __iand__(self: Self, __s: AbstractSet[object]) -> Self: ...
+    def __iand__(self, __s: AbstractSet[object]) -> Self: ...
     def __or__(self, __s: AbstractSet[_S]) -> set[_T | _S]: ...
-    def __ior__(self: Self, __s: AbstractSet[_T]) -> Self: ...  # type: ignore[override,misc]
+    def __ior__(self, __s: AbstractSet[_T]) -> Self: ...  # type: ignore[override,misc]
     def __sub__(self, __s: AbstractSet[_T | None]) -> set[_T]: ...
-    def __isub__(self: Self, __s: AbstractSet[object]) -> Self: ...
+    def __isub__(self, __s: AbstractSet[object]) -> Self: ...
     def __xor__(self, __s: AbstractSet[_S]) -> set[_T | _S]: ...
-    def __ixor__(self: Self, __s: AbstractSet[_T]) -> Self: ...  # type: ignore[override,misc]
+    def __ixor__(self, __s: AbstractSet[_T]) -> Self: ...  # type: ignore[override,misc]
     def __le__(self, __s: AbstractSet[object]) -> bool: ...
     def __lt__(self, __s: AbstractSet[object]) -> bool: ...
     def __ge__(self, __s: AbstractSet[object]) -> bool: ...
@@ -1023,9 +1023,9 @@ class set(MutableSet[_T], Generic[_T]):
 
 class frozenset(AbstractSet[_T_co], Generic[_T_co]):
     @overload
-    def __new__(cls: type[Self]) -> Self: ...
+    def __new__(cls) -> Self: ...
     @overload
-    def __new__(cls: type[Self], __iterable: Iterable[_T_co]) -> Self: ...
+    def __new__(cls, __iterable: Iterable[_T_co]) -> Self: ...
     def copy(self) -> frozenset[_T_co]: ...
     def difference(self, *s: Iterable[object]) -> frozenset[_T_co]: ...
     def intersection(self, *s: Iterable[object]) -> frozenset[_T_co]: ...
@@ -1050,7 +1050,7 @@ class frozenset(AbstractSet[_T_co], Generic[_T_co]):
 
 class enumerate(Iterator[tuple[int, _T]], Generic[_T]):
     def __init__(self, iterable: Iterable[_T], start: int = ...) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[int, _T]: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
@@ -1143,7 +1143,7 @@ if sys.version_info >= (3, 8):
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: Literal[0],
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
         *,
         _feature_version: int = -1,
@@ -1154,7 +1154,7 @@ if sys.version_info >= (3, 8):
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         *,
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
         _feature_version: int = -1,
     ) -> CodeType: ...
@@ -1164,7 +1164,7 @@ if sys.version_info >= (3, 8):
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: Literal[1024],
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
         *,
         _feature_version: int = -1,
@@ -1175,7 +1175,7 @@ if sys.version_info >= (3, 8):
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: int,
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
         *,
         _feature_version: int = -1,
@@ -1188,7 +1188,7 @@ else:
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: Literal[0],
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
     ) -> CodeType: ...
     @overload
@@ -1197,7 +1197,7 @@ else:
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         *,
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
     ) -> CodeType: ...
     @overload
@@ -1206,7 +1206,7 @@ else:
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: Literal[1024],
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
     ) -> _ast.AST: ...
     @overload
@@ -1215,7 +1215,7 @@ else:
         filename: str | ReadableBuffer | _PathLike[Any],
         mode: str,
         flags: int,
-        dont_inherit: int = False,
+        dont_inherit: bool = False,
         optimize: int = -1,
     ) -> Any: ...
 
@@ -1262,7 +1262,7 @@ class filter(Iterator[_T], Generic[_T]):
     def __init__(self, __function: Callable[[_S], TypeGuard[_T]], __iterable: Iterable[_S]) -> None: ...
     @overload
     def __init__(self, __function: Callable[[_T], Any], __iterable: Iterable[_T]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 def format(__value: object, __format_spec: str = "") -> str: ...
@@ -1288,7 +1288,7 @@ def hash(__obj: object) -> int: ...
 def help(request: object = ...) -> None: ...
 def hex(__number: int | SupportsIndex) -> str: ...
 def id(__obj: object) -> int: ...
-def input(__prompt: object = None) -> str: ...
+def input(__prompt: object = "") -> str: ...
 
 class _GetItemIterable(Protocol[_T_co]):
     def __getitem__(self, __i: int) -> _T_co: ...
@@ -1353,35 +1353,35 @@ class map(Iterator[_S], Generic[_S]):
         __iter6: Iterable[Any],
         *iterables: Iterable[Any],
     ) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _S: ...
 
 @overload
 def max(
-    __arg1: SupportsRichComparisonT, __arg2: SupportsRichComparisonT, *_args: SupportsRichComparisonT, key: None = ...
+    __arg1: SupportsRichComparisonT, __arg2: SupportsRichComparisonT, *_args: SupportsRichComparisonT, key: None = None
 ) -> SupportsRichComparisonT: ...
 @overload
 def max(__arg1: _T, __arg2: _T, *_args: _T, key: Callable[[_T], SupportsRichComparison]) -> _T: ...
 @overload
-def max(__iterable: Iterable[SupportsRichComparisonT], *, key: None = ...) -> SupportsRichComparisonT: ...
+def max(__iterable: Iterable[SupportsRichComparisonT], *, key: None = None) -> SupportsRichComparisonT: ...
 @overload
 def max(__iterable: Iterable[_T], *, key: Callable[[_T], SupportsRichComparison]) -> _T: ...
 @overload
-def max(__iterable: Iterable[SupportsRichComparisonT], *, key: None = ..., default: _T) -> SupportsRichComparisonT | _T: ...
+def max(__iterable: Iterable[SupportsRichComparisonT], *, key: None = None, default: _T) -> SupportsRichComparisonT | _T: ...
 @overload
 def max(__iterable: Iterable[_T1], *, key: Callable[[_T1], SupportsRichComparison], default: _T2) -> _T1 | _T2: ...
 @overload
 def min(
-    __arg1: SupportsRichComparisonT, __arg2: SupportsRichComparisonT, *_args: SupportsRichComparisonT, key: None = ...
+    __arg1: SupportsRichComparisonT, __arg2: SupportsRichComparisonT, *_args: SupportsRichComparisonT, key: None = None
 ) -> SupportsRichComparisonT: ...
 @overload
 def min(__arg1: _T, __arg2: _T, *_args: _T, key: Callable[[_T], SupportsRichComparison]) -> _T: ...
 @overload
-def min(__iterable: Iterable[SupportsRichComparisonT], *, key: None = ...) -> SupportsRichComparisonT: ...
+def min(__iterable: Iterable[SupportsRichComparisonT], *, key: None = None) -> SupportsRichComparisonT: ...
 @overload
 def min(__iterable: Iterable[_T], *, key: Callable[[_T], SupportsRichComparison]) -> _T: ...
 @overload
-def min(__iterable: Iterable[SupportsRichComparisonT], *, key: None = ..., default: _T) -> SupportsRichComparisonT | _T: ...
+def min(__iterable: Iterable[SupportsRichComparisonT], *, key: None = None, default: _T) -> SupportsRichComparisonT | _T: ...
 @overload
 def min(__iterable: Iterable[_T1], *, key: Callable[[_T1], SupportsRichComparison], default: _T2) -> _T1 | _T2: ...
 @overload
@@ -1503,7 +1503,7 @@ class _SupportsPow2(Protocol[_E, _T_co]):
     def __pow__(self, __other: _E) -> _T_co: ...
 
 class _SupportsPow3NoneOnly(Protocol[_E, _T_co]):
-    def __pow__(self, __other: _E, __modulo: None = ...) -> _T_co: ...
+    def __pow__(self, __other: _E, __modulo: None = None) -> _T_co: ...
 
 class _SupportsPow3(Protocol[_E, _M, _T_co]):
     def __pow__(self, __other: _E, __modulo: _M) -> _T_co: ...
@@ -1590,7 +1590,7 @@ class reversed(Iterator[_T], Generic[_T]):
     def __init__(self, __sequence: Reversible[_T]) -> None: ...
     @overload
     def __init__(self, __sequence: SupportsLenAndGetItem[_T]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
     def __length_hint__(self) -> int: ...
 
@@ -1734,7 +1734,7 @@ class zip(Iterator[_T_co], Generic[_T_co]):
             *iterables: Iterable[Any],
         ) -> zip[tuple[Any, ...]]: ...
 
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
 # Signature of `builtins.__import__` should be kept identical to `importlib.__import__`
@@ -1764,7 +1764,7 @@ class BaseException:
     __traceback__: TracebackType | None
     def __init__(self, *args: object) -> None: ...
     def __setstate__(self, __state: dict[str, Any] | None) -> None: ...
-    def with_traceback(self: Self, __tb: TracebackType | None) -> Self: ...
+    def with_traceback(self, __tb: TracebackType | None) -> Self: ...
     if sys.version_info >= (3, 11):
         # only present after add_note() is called
         __notes__: list[str]
@@ -1917,7 +1917,7 @@ if sys.version_info >= (3, 11):
 
     # See `check_exception_group.py` for use-cases and comments.
     class BaseExceptionGroup(BaseException, Generic[_BaseExceptionT_co]):
-        def __new__(cls: type[Self], __message: str, __exceptions: Sequence[_BaseExceptionT_co]) -> Self: ...
+        def __new__(cls, __message: str, __exceptions: Sequence[_BaseExceptionT_co]) -> Self: ...
         def __init__(self, __message: str, __exceptions: Sequence[_BaseExceptionT_co]) -> None: ...
         @property
         def message(self) -> str: ...
@@ -1933,7 +1933,7 @@ if sys.version_info >= (3, 11):
         ) -> BaseExceptionGroup[_BaseExceptionT] | None: ...
         @overload
         def subgroup(
-            self: Self, __condition: Callable[[_BaseExceptionT_co | Self], bool]
+            self, __condition: Callable[[_BaseExceptionT_co | Self], bool]
         ) -> BaseExceptionGroup[_BaseExceptionT_co] | None: ...
         @overload
         def split(
@@ -1945,7 +1945,7 @@ if sys.version_info >= (3, 11):
         ) -> tuple[BaseExceptionGroup[_BaseExceptionT] | None, BaseExceptionGroup[_BaseExceptionT_co] | None]: ...
         @overload
         def split(
-            self: Self, __condition: Callable[[_BaseExceptionT_co | Self], bool]
+            self, __condition: Callable[[_BaseExceptionT_co | Self], bool]
         ) -> tuple[BaseExceptionGroup[_BaseExceptionT_co] | None, BaseExceptionGroup[_BaseExceptionT_co] | None]: ...
         # In reality it is `NonEmptySequence`:
         @overload
@@ -1955,7 +1955,7 @@ if sys.version_info >= (3, 11):
         def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
 
     class ExceptionGroup(BaseExceptionGroup[_ExceptionT_co], Exception):
-        def __new__(cls: type[Self], __message: str, __exceptions: Sequence[_ExceptionT_co]) -> Self: ...
+        def __new__(cls, __message: str, __exceptions: Sequence[_ExceptionT_co]) -> Self: ...
         def __init__(self, __message: str, __exceptions: Sequence[_ExceptionT_co]) -> None: ...
         @property
         def exceptions(self) -> tuple[_ExceptionT_co | ExceptionGroup[_ExceptionT_co], ...]: ...
@@ -1965,14 +1965,12 @@ if sys.version_info >= (3, 11):
             self, __condition: type[_ExceptionT] | tuple[type[_ExceptionT], ...]
         ) -> ExceptionGroup[_ExceptionT] | None: ...
         @overload
-        def subgroup(
-            self: Self, __condition: Callable[[_ExceptionT_co | Self], bool]
-        ) -> ExceptionGroup[_ExceptionT_co] | None: ...
+        def subgroup(self, __condition: Callable[[_ExceptionT_co | Self], bool]) -> ExceptionGroup[_ExceptionT_co] | None: ...
         @overload  # type: ignore[override]
         def split(
             self, __condition: type[_ExceptionT] | tuple[type[_ExceptionT], ...]
         ) -> tuple[ExceptionGroup[_ExceptionT] | None, ExceptionGroup[_ExceptionT_co] | None]: ...
         @overload
         def split(
-            self: Self, __condition: Callable[[_ExceptionT_co | Self], bool]
+            self, __condition: Callable[[_ExceptionT_co | Self], bool]
         ) -> tuple[ExceptionGroup[_ExceptionT_co] | None, ExceptionGroup[_ExceptionT_co] | None]: ...
diff --git a/mypy/typeshed/stdlib/bz2.pyi b/mypy/typeshed/stdlib/bz2.pyi
index 8a7151d9e456..9ad80ee6f731 100644
--- a/mypy/typeshed/stdlib/bz2.pyi
+++ b/mypy/typeshed/stdlib/bz2.pyi
@@ -1,10 +1,10 @@
 import _compression
 import sys
 from _compression import BaseStream
-from _typeshed import ReadableBuffer, Self, StrOrBytesPath, WriteableBuffer
+from _typeshed import ReadableBuffer, StrOrBytesPath, WriteableBuffer
 from collections.abc import Iterable
 from typing import IO, Any, Protocol, TextIO, overload
-from typing_extensions import Literal, SupportsIndex, TypeAlias, final
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias, final
 
 __all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor", "open", "compress", "decompress"]
 
@@ -92,7 +92,7 @@ def open(
 ) -> BZ2File | TextIO: ...
 
 class BZ2File(BaseStream, IO[bytes]):
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     if sys.version_info >= (3, 9):
         @overload
         def __init__(self, filename: _WritableFileobj, mode: _WriteBinaryMode, *, compresslevel: int = 9) -> None: ...
diff --git a/mypy/typeshed/stdlib/cProfile.pyi b/mypy/typeshed/stdlib/cProfile.pyi
index 77608b268f6f..8945b21427ab 100644
--- a/mypy/typeshed/stdlib/cProfile.pyi
+++ b/mypy/typeshed/stdlib/cProfile.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import Self, StrOrBytesPath, Unused
+from _typeshed import StrOrBytesPath, Unused
 from collections.abc import Callable
 from types import CodeType
 from typing import Any, TypeVar
-from typing_extensions import ParamSpec, TypeAlias
+from typing_extensions import ParamSpec, Self, TypeAlias
 
 __all__ = ["run", "runctx", "Profile"]
 
@@ -27,11 +27,11 @@ class Profile:
     def dump_stats(self, file: StrOrBytesPath) -> None: ...
     def create_stats(self) -> None: ...
     def snapshot_stats(self) -> None: ...
-    def run(self: Self, cmd: str) -> Self: ...
-    def runctx(self: Self, cmd: str, globals: dict[str, Any], locals: dict[str, Any]) -> Self: ...
+    def run(self, cmd: str) -> Self: ...
+    def runctx(self, cmd: str, globals: dict[str, Any], locals: dict[str, Any]) -> Self: ...
     def runcall(self, __func: Callable[_P, _T], *args: _P.args, **kw: _P.kwargs) -> _T: ...
     if sys.version_info >= (3, 8):
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, *exc_info: Unused) -> None: ...
 
 def label(code: str | CodeType) -> _Label: ...  # undocumented
diff --git a/mypy/typeshed/stdlib/cgi.pyi b/mypy/typeshed/stdlib/cgi.pyi
index 6f5637e3cce1..a2acfa92d463 100644
--- a/mypy/typeshed/stdlib/cgi.pyi
+++ b/mypy/typeshed/stdlib/cgi.pyi
@@ -1,10 +1,11 @@
 import sys
-from _typeshed import Self, SupportsGetItem, SupportsItemAccess, Unused
+from _typeshed import SupportsGetItem, SupportsItemAccess, Unused
 from builtins import list as _list, type as _type
 from collections.abc import Iterable, Iterator, Mapping
 from email.message import Message
 from types import TracebackType
 from typing import IO, Any, Protocol
+from typing_extensions import Self
 
 __all__ = [
     "MiniFieldStorage",
@@ -105,7 +106,7 @@ class FieldStorage:
         max_num_fields: int | None = None,
         separator: str = "&",
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def __iter__(self) -> Iterator[str]: ...
     def __getitem__(self, key: str) -> Any: ...
diff --git a/mypy/typeshed/stdlib/cgitb.pyi b/mypy/typeshed/stdlib/cgitb.pyi
index 04bcbfb0d13d..4c315bf6ca39 100644
--- a/mypy/typeshed/stdlib/cgitb.pyi
+++ b/mypy/typeshed/stdlib/cgitb.pyi
@@ -2,8 +2,9 @@ from _typeshed import OptExcInfo, StrOrBytesPath
 from collections.abc import Callable
 from types import FrameType, TracebackType
 from typing import IO, Any
+from typing_extensions import Final
 
-__UNDEF__: object  # undocumented sentinel
+__UNDEF__: Final[object]  # undocumented sentinel
 
 def reset() -> str: ...  # undocumented
 def small(text: str) -> str: ...  # undocumented
diff --git a/mypy/typeshed/stdlib/codecs.pyi b/mypy/typeshed/stdlib/codecs.pyi
index 33d0e6709923..5a22853b6aee 100644
--- a/mypy/typeshed/stdlib/codecs.pyi
+++ b/mypy/typeshed/stdlib/codecs.pyi
@@ -1,11 +1,11 @@
 import sys
 import types
 from _codecs import *
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from abc import abstractmethod
 from collections.abc import Callable, Generator, Iterable
 from typing import Any, BinaryIO, Protocol, TextIO
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 __all__ = [
     "register",
@@ -110,7 +110,7 @@ class CodecInfo(tuple[_Encoder, _Decoder, _StreamReader, _StreamWriter]):
     def incrementaldecoder(self) -> _IncrementalDecoder: ...
     name: str
     def __new__(
-        cls: type[Self],
+        cls,
         encode: _Encoder,
         decode: _Decoder,
         streamreader: _StreamReader | None = None,
@@ -210,7 +210,7 @@ class StreamWriter(Codec):
     def write(self, object: str) -> None: ...
     def writelines(self, list: Iterable[str]) -> None: ...
     def reset(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
     def __getattr__(self, name: str, getattr: Callable[[str], Any] = ...) -> Any: ...
 
@@ -222,9 +222,9 @@ class StreamReader(Codec):
     def readline(self, size: int | None = None, keepends: bool = True) -> str: ...
     def readlines(self, sizehint: int | None = None, keepends: bool = True) -> list[str]: ...
     def reset(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> str: ...
     def __getattr__(self, name: str, getattr: Callable[[str], Any] = ...) -> Any: ...
 
@@ -237,12 +237,12 @@ class StreamReaderWriter(TextIO):
     def readline(self, size: int | None = None) -> str: ...
     def readlines(self, sizehint: int | None = None) -> list[str]: ...
     def __next__(self) -> str: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def write(self, data: str) -> None: ...  # type: ignore[override]
     def writelines(self, list: Iterable[str]) -> None: ...
     def reset(self) -> None: ...
     def seek(self, offset: int, whence: int = 0) -> None: ...  # type: ignore[override]
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
     # These methods don't actually exist directly, but they are needed to satisfy the TextIO
@@ -271,12 +271,12 @@ class StreamRecoder(BinaryIO):
     def readline(self, size: int | None = None) -> bytes: ...
     def readlines(self, sizehint: int | None = None) -> list[bytes]: ...
     def __next__(self) -> bytes: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def write(self, data: bytes) -> None: ...  # type: ignore[override]
     def writelines(self, list: Iterable[bytes]) -> None: ...
     def reset(self) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
     def seek(self, offset: int, whence: int = 0) -> None: ...  # type: ignore[override]
     # These methods don't actually exist directly, but they are needed to satisfy the BinaryIO
diff --git a/mypy/typeshed/stdlib/collections/__init__.pyi b/mypy/typeshed/stdlib/collections/__init__.pyi
index d4c537b1384e..893a289d3cb1 100644
--- a/mypy/typeshed/stdlib/collections/__init__.pyi
+++ b/mypy/typeshed/stdlib/collections/__init__.pyi
@@ -1,8 +1,8 @@
 import sys
 from _collections_abc import dict_items, dict_keys, dict_values
-from _typeshed import Self, SupportsKeysAndGetItem, SupportsRichComparison, SupportsRichComparisonT
+from _typeshed import SupportsKeysAndGetItem, SupportsRichComparison, SupportsRichComparisonT
 from typing import Any, Generic, NoReturn, TypeVar, overload
-from typing_extensions import SupportsIndex, final
+from typing_extensions import Self, SupportsIndex, final
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -68,8 +68,8 @@ class UserDict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     def __delitem__(self, key: _KT) -> None: ...
     def __iter__(self) -> Iterator[_KT]: ...
     def __contains__(self, key: object) -> bool: ...
-    def copy(self: Self) -> Self: ...
-    def __copy__(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
+    def __copy__(self) -> Self: ...
 
     # `UserDict.fromkeys` has the same semantics as `dict.fromkeys`, so should be kept in line with `dict.fromkeys`.
     # TODO: Much like `dict.fromkeys`, the true signature of `UserDict.fromkeys` is inexpressible in the current type system.
@@ -85,9 +85,9 @@ class UserDict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
         def __ror__(self, other: UserDict[_T1, _T2] | dict[_T1, _T2]) -> UserDict[_KT | _T1, _VT | _T2]: ...  # type: ignore[misc]
         # UserDict.__ior__ should be kept roughly in line with MutableMapping.update()
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
+        def __ior__(self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
         @overload
-        def __ior__(self: Self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
+        def __ior__(self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
 
 class UserList(MutableSequence[_T]):
     data: list[_T]
@@ -105,32 +105,32 @@ class UserList(MutableSequence[_T]):
     @overload
     def __getitem__(self, i: SupportsIndex) -> _T: ...
     @overload
-    def __getitem__(self: Self, i: slice) -> Self: ...
+    def __getitem__(self, i: slice) -> Self: ...
     @overload
     def __setitem__(self, i: SupportsIndex, item: _T) -> None: ...
     @overload
     def __setitem__(self, i: slice, item: Iterable[_T]) -> None: ...
     def __delitem__(self, i: SupportsIndex | slice) -> None: ...
-    def __add__(self: Self, other: Iterable[_T]) -> Self: ...
-    def __radd__(self: Self, other: Iterable[_T]) -> Self: ...
-    def __iadd__(self: Self, other: Iterable[_T]) -> Self: ...
-    def __mul__(self: Self, n: int) -> Self: ...
-    def __rmul__(self: Self, n: int) -> Self: ...
-    def __imul__(self: Self, n: int) -> Self: ...
+    def __add__(self, other: Iterable[_T]) -> Self: ...
+    def __radd__(self, other: Iterable[_T]) -> Self: ...
+    def __iadd__(self, other: Iterable[_T]) -> Self: ...
+    def __mul__(self, n: int) -> Self: ...
+    def __rmul__(self, n: int) -> Self: ...
+    def __imul__(self, n: int) -> Self: ...
     def append(self, item: _T) -> None: ...
     def insert(self, i: int, item: _T) -> None: ...
     def pop(self, i: int = -1) -> _T: ...
     def remove(self, item: _T) -> None: ...
-    def copy(self: Self) -> Self: ...
-    def __copy__(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
+    def __copy__(self) -> Self: ...
     def count(self, item: _T) -> int: ...
     # All arguments are passed to `list.index` at runtime, so the signature should be kept in line with `list.index`.
-    def index(self, item: _T, __start: SupportsIndex = ..., __stop: SupportsIndex = ...) -> int: ...
+    def index(self, item: _T, __start: SupportsIndex = 0, __stop: SupportsIndex = sys.maxsize) -> int: ...
     # All arguments are passed to `list.sort` at runtime, so the signature should be kept in line with `list.sort`.
     @overload
-    def sort(self: UserList[SupportsRichComparisonT], *, key: None = ..., reverse: bool = ...) -> None: ...
+    def sort(self: UserList[SupportsRichComparisonT], *, key: None = None, reverse: bool = False) -> None: ...
     @overload
-    def sort(self, *, key: Callable[[_T], SupportsRichComparison], reverse: bool = ...) -> None: ...
+    def sort(self, *, key: Callable[[_T], SupportsRichComparison], reverse: bool = False) -> None: ...
     def extend(self, other: Iterable[_T]) -> None: ...
 
 class UserString(Sequence[UserString]):
@@ -147,30 +147,30 @@ class UserString(Sequence[UserString]):
     def __eq__(self, string: object) -> bool: ...
     def __contains__(self, char: object) -> bool: ...
     def __len__(self) -> int: ...
-    def __getitem__(self: Self, index: SupportsIndex | slice) -> Self: ...
-    def __iter__(self: Self) -> Iterator[Self]: ...
-    def __reversed__(self: Self) -> Iterator[Self]: ...
-    def __add__(self: Self, other: object) -> Self: ...
-    def __radd__(self: Self, other: object) -> Self: ...
-    def __mul__(self: Self, n: int) -> Self: ...
-    def __rmul__(self: Self, n: int) -> Self: ...
-    def __mod__(self: Self, args: Any) -> Self: ...
+    def __getitem__(self, index: SupportsIndex | slice) -> Self: ...
+    def __iter__(self) -> Iterator[Self]: ...
+    def __reversed__(self) -> Iterator[Self]: ...
+    def __add__(self, other: object) -> Self: ...
+    def __radd__(self, other: object) -> Self: ...
+    def __mul__(self, n: int) -> Self: ...
+    def __rmul__(self, n: int) -> Self: ...
+    def __mod__(self, args: Any) -> Self: ...
     if sys.version_info >= (3, 8):
-        def __rmod__(self: Self, template: object) -> Self: ...
+        def __rmod__(self, template: object) -> Self: ...
     else:
-        def __rmod__(self: Self, format: Any) -> Self: ...
+        def __rmod__(self, format: Any) -> Self: ...
 
-    def capitalize(self: Self) -> Self: ...
-    def casefold(self: Self) -> Self: ...
-    def center(self: Self, width: int, *args: Any) -> Self: ...
+    def capitalize(self) -> Self: ...
+    def casefold(self) -> Self: ...
+    def center(self, width: int, *args: Any) -> Self: ...
     def count(self, sub: str | UserString, start: int = 0, end: int = sys.maxsize) -> int: ...
     if sys.version_info >= (3, 8):
         def encode(self: UserString, encoding: str | None = "utf-8", errors: str | None = "strict") -> bytes: ...
     else:
-        def encode(self: Self, encoding: str | None = None, errors: str | None = None) -> Self: ...
+        def encode(self, encoding: str | None = None, errors: str | None = None) -> Self: ...
 
     def endswith(self, suffix: str | tuple[str, ...], start: int | None = 0, end: int | None = sys.maxsize) -> bool: ...
-    def expandtabs(self: Self, tabsize: int = 8) -> Self: ...
+    def expandtabs(self, tabsize: int = 8) -> Self: ...
     def find(self, sub: str | UserString, start: int = 0, end: int = sys.maxsize) -> int: ...
     def format(self, *args: Any, **kwds: Any) -> str: ...
     def format_map(self, mapping: Mapping[str, Any]) -> str: ...
@@ -188,63 +188,63 @@ class UserString(Sequence[UserString]):
     def isupper(self) -> bool: ...
     def isascii(self) -> bool: ...
     def join(self, seq: Iterable[str]) -> str: ...
-    def ljust(self: Self, width: int, *args: Any) -> Self: ...
-    def lower(self: Self) -> Self: ...
-    def lstrip(self: Self, chars: str | None = None) -> Self: ...
+    def ljust(self, width: int, *args: Any) -> Self: ...
+    def lower(self) -> Self: ...
+    def lstrip(self, chars: str | None = None) -> Self: ...
     maketrans = str.maketrans
     def partition(self, sep: str) -> tuple[str, str, str]: ...
     if sys.version_info >= (3, 9):
-        def removeprefix(self: Self, __prefix: str | UserString) -> Self: ...
-        def removesuffix(self: Self, __suffix: str | UserString) -> Self: ...
+        def removeprefix(self, __prefix: str | UserString) -> Self: ...
+        def removesuffix(self, __suffix: str | UserString) -> Self: ...
 
-    def replace(self: Self, old: str | UserString, new: str | UserString, maxsplit: int = -1) -> Self: ...
+    def replace(self, old: str | UserString, new: str | UserString, maxsplit: int = -1) -> Self: ...
     def rfind(self, sub: str | UserString, start: int = 0, end: int = sys.maxsize) -> int: ...
     def rindex(self, sub: str | UserString, start: int = 0, end: int = sys.maxsize) -> int: ...
-    def rjust(self: Self, width: int, *args: Any) -> Self: ...
+    def rjust(self, width: int, *args: Any) -> Self: ...
     def rpartition(self, sep: str) -> tuple[str, str, str]: ...
-    def rstrip(self: Self, chars: str | None = None) -> Self: ...
+    def rstrip(self, chars: str | None = None) -> Self: ...
     def split(self, sep: str | None = None, maxsplit: int = -1) -> list[str]: ...
     def rsplit(self, sep: str | None = None, maxsplit: int = -1) -> list[str]: ...
     def splitlines(self, keepends: bool = False) -> list[str]: ...
     def startswith(self, prefix: str | tuple[str, ...], start: int | None = 0, end: int | None = sys.maxsize) -> bool: ...
-    def strip(self: Self, chars: str | None = None) -> Self: ...
-    def swapcase(self: Self) -> Self: ...
-    def title(self: Self) -> Self: ...
-    def translate(self: Self, *args: Any) -> Self: ...
-    def upper(self: Self) -> Self: ...
-    def zfill(self: Self, width: int) -> Self: ...
+    def strip(self, chars: str | None = None) -> Self: ...
+    def swapcase(self) -> Self: ...
+    def title(self) -> Self: ...
+    def translate(self, *args: Any) -> Self: ...
+    def upper(self) -> Self: ...
+    def zfill(self, width: int) -> Self: ...
 
 class deque(MutableSequence[_T], Generic[_T]):
     @property
     def maxlen(self) -> int | None: ...
     @overload
-    def __init__(self, *, maxlen: int | None = ...) -> None: ...
+    def __init__(self, *, maxlen: int | None = None) -> None: ...
     @overload
-    def __init__(self, iterable: Iterable[_T], maxlen: int | None = ...) -> None: ...
+    def __init__(self, iterable: Iterable[_T], maxlen: int | None = None) -> None: ...
     def append(self, __x: _T) -> None: ...
     def appendleft(self, __x: _T) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def count(self, __x: _T) -> int: ...
     def extend(self, __iterable: Iterable[_T]) -> None: ...
     def extendleft(self, __iterable: Iterable[_T]) -> None: ...
     def insert(self, __i: int, __x: _T) -> None: ...
-    def index(self, __x: _T, __start: int = ..., __stop: int = ...) -> int: ...
+    def index(self, __x: _T, __start: int = 0, __stop: int = ...) -> int: ...
     def pop(self) -> _T: ...  # type: ignore[override]
     def popleft(self) -> _T: ...
     def remove(self, __value: _T) -> None: ...
-    def rotate(self, __n: int = ...) -> None: ...
-    def __copy__(self: Self) -> Self: ...
+    def rotate(self, __n: int = 1) -> None: ...
+    def __copy__(self) -> Self: ...
     def __len__(self) -> int: ...
     # These methods of deque don't take slices, unlike MutableSequence, hence the type: ignores
     def __getitem__(self, __index: SupportsIndex) -> _T: ...  # type: ignore[override]
     def __setitem__(self, __i: SupportsIndex, __x: _T) -> None: ...  # type: ignore[override]
     def __delitem__(self, __i: SupportsIndex) -> None: ...  # type: ignore[override]
     def __contains__(self, __o: object) -> bool: ...
-    def __reduce__(self: Self) -> tuple[type[Self], tuple[()], None, Iterator[_T]]: ...
-    def __iadd__(self: Self, __iterable: Iterable[_T]) -> Self: ...
-    def __add__(self: Self, __other: Self) -> Self: ...
-    def __mul__(self: Self, __other: int) -> Self: ...
-    def __imul__(self: Self, __other: int) -> Self: ...
+    def __reduce__(self) -> tuple[type[Self], tuple[()], None, Iterator[_T]]: ...
+    def __iadd__(self, __iterable: Iterable[_T]) -> Self: ...
+    def __add__(self, __other: Self) -> Self: ...
+    def __mul__(self, __other: int) -> Self: ...
+    def __imul__(self, __other: int) -> Self: ...
     def __lt__(self, __other: deque[_T]) -> bool: ...
     def __le__(self, __other: deque[_T]) -> bool: ...
     def __gt__(self, __other: deque[_T]) -> bool: ...
@@ -261,7 +261,7 @@ class Counter(dict[_T, int], Generic[_T]):
     def __init__(self, __mapping: SupportsKeysAndGetItem[_T, int]) -> None: ...
     @overload
     def __init__(self, __iterable: Iterable[_T]) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def elements(self) -> Iterator[_T]: ...
     def most_common(self, n: int | None = None) -> list[tuple[_T, int]]: ...
     @classmethod
@@ -281,9 +281,9 @@ class Counter(dict[_T, int], Generic[_T]):
     @overload  # type: ignore[override]
     def update(self, __m: Mapping[_T, int], **kwargs: int) -> None: ...
     @overload
-    def update(self, __m: Iterable[_T], **kwargs: int) -> None: ...
+    def update(self, __iterable: Iterable[_T], **kwargs: int) -> None: ...
     @overload
-    def update(self, __m: None = ..., **kwargs: int) -> None: ...
+    def update(self, __iterable: None = None, **kwargs: int) -> None: ...
     def __missing__(self, key: _T) -> int: ...
     def __delitem__(self, elem: object) -> None: ...
     if sys.version_info >= (3, 10):
@@ -297,10 +297,10 @@ class Counter(dict[_T, int], Generic[_T]):
     def __pos__(self) -> Counter[_T]: ...
     def __neg__(self) -> Counter[_T]: ...
     # several type: ignores because __iadd__ is supposedly incompatible with __add__, etc.
-    def __iadd__(self: Self, other: Counter[_T]) -> Self: ...  # type: ignore[misc]
-    def __isub__(self: Self, other: Counter[_T]) -> Self: ...
-    def __iand__(self: Self, other: Counter[_T]) -> Self: ...
-    def __ior__(self: Self, other: Counter[_T]) -> Self: ...  # type: ignore[override,misc]
+    def __iadd__(self, other: Counter[_T]) -> Self: ...  # type: ignore[misc]
+    def __isub__(self, other: Counter[_T]) -> Self: ...
+    def __iand__(self, other: Counter[_T]) -> Self: ...
+    def __ior__(self, other: Counter[_T]) -> Self: ...  # type: ignore[override,misc]
     if sys.version_info >= (3, 10):
         def total(self) -> int: ...
         def __le__(self, other: Counter[Any]) -> bool: ...
@@ -338,7 +338,7 @@ class _odict_values(dict_values[_KT_co, _VT_co], Reversible[_VT_co], Generic[_KT
 class OrderedDict(dict[_KT, _VT], Reversible[_KT], Generic[_KT, _VT]):
     def popitem(self, last: bool = True) -> tuple[_KT, _VT]: ...
     def move_to_end(self, key: _KT, last: bool = True) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def __reversed__(self) -> Iterator[_KT]: ...
     def keys(self) -> _odict_keys[_KT, _VT]: ...
     def items(self) -> _odict_items[_KT, _VT]: ...
@@ -387,15 +387,15 @@ class defaultdict(dict[_KT, _VT], Generic[_KT, _VT]):
         **kwargs: _VT,
     ) -> None: ...
     def __missing__(self, __key: _KT) -> _VT: ...
-    def __copy__(self: Self) -> Self: ...
-    def copy(self: Self) -> Self: ...
+    def __copy__(self) -> Self: ...
+    def copy(self) -> Self: ...
 
 class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     maps: list[MutableMapping[_KT, _VT]]
     def __init__(self, *maps: MutableMapping[_KT, _VT]) -> None: ...
-    def new_child(self: Self, m: MutableMapping[_KT, _VT] | None = None) -> Self: ...
+    def new_child(self, m: MutableMapping[_KT, _VT] | None = None) -> Self: ...
     @property
-    def parents(self: Self) -> Self: ...
+    def parents(self) -> Self: ...
     def __setitem__(self, key: _KT, value: _VT) -> None: ...
     def __delitem__(self, key: _KT) -> None: ...
     def __getitem__(self, key: _KT) -> _VT: ...
@@ -412,13 +412,13 @@ class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     @overload
     def pop(self, key: _KT) -> _VT: ...
     @overload
-    def pop(self, key: _KT, default: _VT | _T = ...) -> _VT | _T: ...
-    def copy(self: Self) -> Self: ...
+    def pop(self, key: _KT, default: _VT | _T) -> _VT | _T: ...
+    def copy(self) -> Self: ...
     __copy__ = copy
     # All arguments to `fromkeys` are passed to `dict.fromkeys` at runtime, so the signature should be kept in line with `dict.fromkeys`.
     @classmethod
     @overload
-    def fromkeys(cls, iterable: Iterable[_T], __value: None = ...) -> ChainMap[_T, Any | None]: ...
+    def fromkeys(cls, iterable: Iterable[_T], __value: None = None) -> ChainMap[_T, Any | None]: ...
     @classmethod
     @overload
     def fromkeys(cls, __iterable: Iterable[_T], __value: _S) -> ChainMap[_T, _S]: ...
@@ -427,6 +427,6 @@ class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
         def __ror__(self, other: Mapping[_T1, _T2]) -> ChainMap[_KT | _T1, _VT | _T2]: ...
         # ChainMap.__ior__ should be kept roughly in line with MutableMapping.update()
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
+        def __ior__(self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
         @overload
-        def __ior__(self: Self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
+        def __ior__(self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
diff --git a/mypy/typeshed/stdlib/concurrent/futures/_base.pyi b/mypy/typeshed/stdlib/concurrent/futures/_base.pyi
index 64084a884433..e792cf1a83c0 100644
--- a/mypy/typeshed/stdlib/concurrent/futures/_base.pyi
+++ b/mypy/typeshed/stdlib/concurrent/futures/_base.pyi
@@ -1,11 +1,11 @@
 import sys
 import threading
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from collections.abc import Callable, Iterable, Iterator, Sequence
 from logging import Logger
 from types import TracebackType
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import Literal, ParamSpec, SupportsIndex
+from typing_extensions import Literal, ParamSpec, Self, SupportsIndex
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -62,7 +62,7 @@ class Executor:
     else:
         def shutdown(self, wait: bool = True) -> None: ...
 
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> bool | None: ...
diff --git a/mypy/typeshed/stdlib/contextlib.pyi b/mypy/typeshed/stdlib/contextlib.pyi
index 522285abbc72..feb43aabb039 100644
--- a/mypy/typeshed/stdlib/contextlib.pyi
+++ b/mypy/typeshed/stdlib/contextlib.pyi
@@ -1,11 +1,11 @@
 import abc
 import sys
-from _typeshed import FileDescriptorOrPath, Self, Unused
+from _typeshed import FileDescriptorOrPath, Unused
 from abc import abstractmethod
 from collections.abc import AsyncGenerator, AsyncIterator, Awaitable, Callable, Generator, Iterator
 from types import TracebackType
 from typing import IO, Any, Generic, Protocol, TypeVar, overload, runtime_checkable
-from typing_extensions import ParamSpec, TypeAlias
+from typing_extensions import ParamSpec, Self, TypeAlias
 
 __all__ = [
     "contextmanager",
@@ -140,9 +140,9 @@ class ExitStack(metaclass=abc.ABCMeta):
     def enter_context(self, cm: AbstractContextManager[_T]) -> _T: ...
     def push(self, exit: _CM_EF) -> _CM_EF: ...
     def callback(self, __callback: Callable[_P, _T], *args: _P.args, **kwds: _P.kwargs) -> Callable[_P, _T]: ...
-    def pop_all(self: Self) -> Self: ...
+    def pop_all(self) -> Self: ...
     def close(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, __exc_type: type[BaseException] | None, __exc_value: BaseException | None, __traceback: TracebackType | None
     ) -> bool: ...
@@ -163,9 +163,9 @@ class AsyncExitStack(metaclass=abc.ABCMeta):
     def push_async_callback(
         self, __callback: Callable[_P, Awaitable[_T]], *args: _P.args, **kwds: _P.kwargs
     ) -> Callable[_P, Awaitable[_T]]: ...
-    def pop_all(self: Self) -> Self: ...
+    def pop_all(self) -> Self: ...
     async def aclose(self) -> None: ...
-    async def __aenter__(self: Self) -> Self: ...
+    async def __aenter__(self) -> Self: ...
     async def __aexit__(
         self, __exc_type: type[BaseException] | None, __exc_value: BaseException | None, __traceback: TracebackType | None
     ) -> bool: ...
diff --git a/mypy/typeshed/stdlib/copyreg.pyi b/mypy/typeshed/stdlib/copyreg.pyi
index 07338b422385..8f7fd957fc52 100644
--- a/mypy/typeshed/stdlib/copyreg.pyi
+++ b/mypy/typeshed/stdlib/copyreg.pyi
@@ -1,9 +1,9 @@
 from collections.abc import Callable, Hashable
-from typing import Any, SupportsInt, TypeVar, Union
+from typing import Any, SupportsInt, TypeVar
 from typing_extensions import TypeAlias
 
 _T = TypeVar("_T")
-_Reduce: TypeAlias = Union[tuple[Callable[..., _T], tuple[Any, ...]], tuple[Callable[..., _T], tuple[Any, ...], Any | None]]
+_Reduce: TypeAlias = tuple[Callable[..., _T], tuple[Any, ...]] | tuple[Callable[..., _T], tuple[Any, ...], Any | None]
 
 __all__ = ["pickle", "constructor", "add_extension", "remove_extension", "clear_extension_cache"]
 
diff --git a/mypy/typeshed/stdlib/csv.pyi b/mypy/typeshed/stdlib/csv.pyi
index 13b483b219d5..234b189fb3db 100644
--- a/mypy/typeshed/stdlib/csv.pyi
+++ b/mypy/typeshed/stdlib/csv.pyi
@@ -21,10 +21,10 @@ from _csv import (
     unregister_dialect as unregister_dialect,
     writer as writer,
 )
-from _typeshed import Self, SupportsWrite
+from _typeshed import SupportsWrite
 from collections.abc import Collection, Iterable, Iterator, Mapping, Sequence
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 if sys.version_info >= (3, 8):
     from builtins import dict as _DictReadMapping
@@ -107,7 +107,7 @@ class DictReader(Generic[_T], Iterator[_DictReadMapping[_T | Any, str | Any]]):
         quoting: _QuotingType = ...,
         strict: bool = ...,
     ) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _DictReadMapping[_T | Any, str | Any]: ...
     if sys.version_info >= (3, 12):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
diff --git a/mypy/typeshed/stdlib/ctypes/__init__.pyi b/mypy/typeshed/stdlib/ctypes/__init__.pyi
index 5c4299989d92..497e2f7db70b 100644
--- a/mypy/typeshed/stdlib/ctypes/__init__.pyi
+++ b/mypy/typeshed/stdlib/ctypes/__init__.pyi
@@ -1,10 +1,10 @@
 import sys
 from _ctypes import RTLD_GLOBAL as RTLD_GLOBAL, RTLD_LOCAL as RTLD_LOCAL
-from _typeshed import ReadableBuffer, Self, WriteableBuffer
+from _typeshed import ReadableBuffer, WriteableBuffer
 from abc import abstractmethod
 from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
-from typing import Any, ClassVar, Generic, TypeVar, Union as _UnionT, overload
-from typing_extensions import TypeAlias
+from typing import Any, ClassVar, Generic, TypeVar, overload
+from typing_extensions import Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -77,21 +77,21 @@ class _CData(metaclass=_CDataMeta):
     _b_needsfree_: bool
     _objects: Mapping[Any, int] | None
     @classmethod
-    def from_buffer(cls: type[Self], source: WriteableBuffer, offset: int = ...) -> Self: ...
+    def from_buffer(cls, source: WriteableBuffer, offset: int = ...) -> Self: ...
     @classmethod
-    def from_buffer_copy(cls: type[Self], source: ReadableBuffer, offset: int = ...) -> Self: ...
+    def from_buffer_copy(cls, source: ReadableBuffer, offset: int = ...) -> Self: ...
     @classmethod
-    def from_address(cls: type[Self], address: int) -> Self: ...
+    def from_address(cls, address: int) -> Self: ...
     @classmethod
-    def from_param(cls: type[Self], obj: Any) -> Self | _CArgObject: ...
+    def from_param(cls, obj: Any) -> Self | _CArgObject: ...
     @classmethod
-    def in_dll(cls: type[Self], library: CDLL, name: str) -> Self: ...
+    def in_dll(cls, library: CDLL, name: str) -> Self: ...
 
 class _CanCastTo(_CData): ...
 class _PointerLike(_CanCastTo): ...
 
 _ECT: TypeAlias = Callable[[type[_CData] | None, _FuncPointer, tuple[_CData, ...]], _CData]
-_PF: TypeAlias = _UnionT[tuple[int], tuple[int, str], tuple[int, str, Any]]
+_PF: TypeAlias = tuple[int] | tuple[int, str] | tuple[int, str, Any]
 
 class _FuncPointer(_PointerLike, _CData):
     restype: type[_CData] | Callable[[int], Any] | None
diff --git a/mypy/typeshed/stdlib/dataclasses.pyi b/mypy/typeshed/stdlib/dataclasses.pyi
index 3b7327137ec5..c02aaabe6196 100644
--- a/mypy/typeshed/stdlib/dataclasses.pyi
+++ b/mypy/typeshed/stdlib/dataclasses.pyi
@@ -1,9 +1,10 @@
 import enum
 import sys
 import types
+from _typeshed import DataclassInstance
 from builtins import type as Type  # alias to avoid name clashes with fields named "type"
 from collections.abc import Callable, Iterable, Mapping
-from typing import Any, ClassVar, Generic, Protocol, TypeVar, overload
+from typing import Any, Generic, Protocol, TypeVar, overload
 from typing_extensions import Literal, TypeAlias, TypeGuard
 
 if sys.version_info >= (3, 9):
@@ -30,10 +31,7 @@ __all__ = [
 if sys.version_info >= (3, 10):
     __all__ += ["KW_ONLY"]
 
-class _DataclassInstance(Protocol):
-    __dataclass_fields__: ClassVar[dict[str, Field[Any]]]
-
-_DataclassT = TypeVar("_DataclassT", bound=_DataclassInstance)
+_DataclassT = TypeVar("_DataclassT", bound=DataclassInstance)
 
 # define _MISSING_TYPE as an enum within the type stubs,
 # even though that is not really its type at runtime
@@ -49,26 +47,26 @@ if sys.version_info >= (3, 10):
     class KW_ONLY: ...
 
 @overload
-def asdict(obj: _DataclassInstance) -> dict[str, Any]: ...
+def asdict(obj: DataclassInstance) -> dict[str, Any]: ...
 @overload
-def asdict(obj: _DataclassInstance, *, dict_factory: Callable[[list[tuple[str, Any]]], _T]) -> _T: ...
+def asdict(obj: DataclassInstance, *, dict_factory: Callable[[list[tuple[str, Any]]], _T]) -> _T: ...
 @overload
-def astuple(obj: _DataclassInstance) -> tuple[Any, ...]: ...
+def astuple(obj: DataclassInstance) -> tuple[Any, ...]: ...
 @overload
-def astuple(obj: _DataclassInstance, *, tuple_factory: Callable[[list[Any]], _T]) -> _T: ...
+def astuple(obj: DataclassInstance, *, tuple_factory: Callable[[list[Any]], _T]) -> _T: ...
 
 if sys.version_info >= (3, 8):
     # cls argument is now positional-only
     @overload
-    def dataclass(__cls: type[_T]) -> type[_T]: ...
-    @overload
     def dataclass(__cls: None) -> Callable[[type[_T]], type[_T]]: ...
+    @overload
+    def dataclass(__cls: type[_T]) -> type[_T]: ...
 
 else:
-    @overload
-    def dataclass(_cls: type[_T]) -> type[_T]: ...
     @overload
     def dataclass(_cls: None) -> Callable[[type[_T]], type[_T]]: ...
+    @overload
+    def dataclass(_cls: type[_T]) -> type[_T]: ...
 
 if sys.version_info >= (3, 11):
     @overload
@@ -223,13 +221,13 @@ else:
         metadata: Mapping[Any, Any] | None = None,
     ) -> Any: ...
 
-def fields(class_or_instance: _DataclassInstance | type[_DataclassInstance]) -> tuple[Field[Any], ...]: ...
+def fields(class_or_instance: DataclassInstance | type[DataclassInstance]) -> tuple[Field[Any], ...]: ...
 @overload
-def is_dataclass(obj: _DataclassInstance | type[_DataclassInstance]) -> Literal[True]: ...
+def is_dataclass(obj: DataclassInstance | type[DataclassInstance]) -> Literal[True]: ...
 @overload
-def is_dataclass(obj: type) -> TypeGuard[type[_DataclassInstance]]: ...
+def is_dataclass(obj: type) -> TypeGuard[type[DataclassInstance]]: ...
 @overload
-def is_dataclass(obj: object) -> TypeGuard[_DataclassInstance | type[_DataclassInstance]]: ...
+def is_dataclass(obj: object) -> TypeGuard[DataclassInstance | type[DataclassInstance]]: ...
 
 class FrozenInstanceError(AttributeError): ...
 
diff --git a/mypy/typeshed/stdlib/datetime.pyi b/mypy/typeshed/stdlib/datetime.pyi
index 377ef0067485..4da5501ce76d 100644
--- a/mypy/typeshed/stdlib/datetime.pyi
+++ b/mypy/typeshed/stdlib/datetime.pyi
@@ -1,9 +1,8 @@
 import sys
-from _typeshed import Self
 from abc import abstractmethod
 from time import struct_time
 from typing import ClassVar, NamedTuple, NoReturn, TypeVar, overload
-from typing_extensions import Literal, TypeAlias, final
+from typing_extensions import Literal, Self, TypeAlias, final
 
 if sys.version_info >= (3, 11):
     __all__ = ("date", "datetime", "time", "timedelta", "timezone", "tzinfo", "MINYEAR", "MAXYEAR", "UTC")
@@ -50,18 +49,18 @@ class date:
     min: ClassVar[date]
     max: ClassVar[date]
     resolution: ClassVar[timedelta]
-    def __new__(cls: type[Self], year: int, month: int, day: int) -> Self: ...
+    def __new__(cls, year: int, month: int, day: int) -> Self: ...
     @classmethod
-    def fromtimestamp(cls: type[Self], __timestamp: float) -> Self: ...
+    def fromtimestamp(cls, __timestamp: float) -> Self: ...
     @classmethod
-    def today(cls: type[Self]) -> Self: ...
+    def today(cls) -> Self: ...
     @classmethod
-    def fromordinal(cls: type[Self], __n: int) -> Self: ...
+    def fromordinal(cls, __n: int) -> Self: ...
     @classmethod
-    def fromisoformat(cls: type[Self], __date_string: str) -> Self: ...
+    def fromisoformat(cls, __date_string: str) -> Self: ...
     if sys.version_info >= (3, 8):
         @classmethod
-        def fromisocalendar(cls: type[Self], year: int, week: int, day: int) -> Self: ...
+        def fromisocalendar(cls, year: int, week: int, day: int) -> Self: ...
 
     @property
     def year(self) -> int: ...
@@ -82,16 +81,16 @@ class date:
     def isoformat(self) -> str: ...
     def timetuple(self) -> struct_time: ...
     def toordinal(self) -> int: ...
-    def replace(self: Self, year: int = ..., month: int = ..., day: int = ...) -> Self: ...
+    def replace(self, year: int = ..., month: int = ..., day: int = ...) -> Self: ...
     def __le__(self, __other: date) -> bool: ...
     def __lt__(self, __other: date) -> bool: ...
     def __ge__(self, __other: date) -> bool: ...
     def __gt__(self, __other: date) -> bool: ...
     if sys.version_info >= (3, 8):
-        def __add__(self: Self, __other: timedelta) -> Self: ...
-        def __radd__(self: Self, __other: timedelta) -> Self: ...
+        def __add__(self, __other: timedelta) -> Self: ...
+        def __radd__(self, __other: timedelta) -> Self: ...
         @overload
-        def __sub__(self: Self, __other: timedelta) -> Self: ...
+        def __sub__(self, __other: timedelta) -> Self: ...
         @overload
         def __sub__(self, __other: datetime) -> NoReturn: ...
         @overload
@@ -119,7 +118,7 @@ class time:
     max: ClassVar[time]
     resolution: ClassVar[timedelta]
     def __new__(
-        cls: type[Self],
+        cls,
         hour: int = ...,
         minute: int = ...,
         second: int = ...,
@@ -146,7 +145,7 @@ class time:
     def __gt__(self, __other: time) -> bool: ...
     def isoformat(self, timespec: str = ...) -> str: ...
     @classmethod
-    def fromisoformat(cls: type[Self], __time_string: str) -> Self: ...
+    def fromisoformat(cls, __time_string: str) -> Self: ...
     # On <3.12, the name of the parameter in the pure-Python implementation
     # didn't match the name in the C implementation,
     # meaning it is only *safe* to pass it as a keyword argument on 3.12+
@@ -160,7 +159,7 @@ class time:
     def tzname(self) -> str | None: ...
     def dst(self) -> timedelta | None: ...
     def replace(
-        self: Self,
+        self,
         hour: int = ...,
         minute: int = ...,
         second: int = ...,
@@ -178,7 +177,7 @@ class timedelta:
     max: ClassVar[timedelta]
     resolution: ClassVar[timedelta]
     def __new__(
-        cls: type[Self],
+        cls,
         days: float = ...,
         seconds: float = ...,
         microseconds: float = ...,
@@ -223,7 +222,7 @@ class datetime(date):
     min: ClassVar[datetime]
     max: ClassVar[datetime]
     def __new__(
-        cls: type[Self],
+        cls,
         year: int,
         month: int,
         day: int,
@@ -252,35 +251,35 @@ class datetime(date):
     # meaning it is only *safe* to pass it as a keyword argument on 3.12+
     if sys.version_info >= (3, 12):
         @classmethod
-        def fromtimestamp(cls: type[Self], timestamp: float, tz: _TzInfo | None = ...) -> Self: ...
+        def fromtimestamp(cls, timestamp: float, tz: _TzInfo | None = ...) -> Self: ...
     else:
         @classmethod
-        def fromtimestamp(cls: type[Self], __timestamp: float, tz: _TzInfo | None = ...) -> Self: ...
+        def fromtimestamp(cls, __timestamp: float, tz: _TzInfo | None = ...) -> Self: ...
 
     @classmethod
-    def utcfromtimestamp(cls: type[Self], __t: float) -> Self: ...
+    def utcfromtimestamp(cls, __t: float) -> Self: ...
     if sys.version_info >= (3, 8):
         @classmethod
-        def now(cls: type[Self], tz: _TzInfo | None = None) -> Self: ...
+        def now(cls, tz: _TzInfo | None = None) -> Self: ...
     else:
         @overload
         @classmethod
-        def now(cls: type[Self], tz: None = None) -> Self: ...
+        def now(cls, tz: None = None) -> Self: ...
         @overload
         @classmethod
         def now(cls, tz: _TzInfo) -> datetime: ...
 
     @classmethod
-    def utcnow(cls: type[Self]) -> Self: ...
+    def utcnow(cls) -> Self: ...
     @classmethod
-    def combine(cls, date: _Date, time: _Time, tzinfo: _TzInfo | None = ...) -> datetime: ...
+    def combine(cls, date: _Date, time: _Time, tzinfo: _TzInfo | None = ...) -> Self: ...
     def timestamp(self) -> float: ...
     def utctimetuple(self) -> struct_time: ...
     def date(self) -> _Date: ...
     def time(self) -> _Time: ...
     def timetz(self) -> _Time: ...
     def replace(
-        self: Self,
+        self,
         year: int = ...,
         month: int = ...,
         day: int = ...,
@@ -293,13 +292,13 @@ class datetime(date):
         fold: int = ...,
     ) -> Self: ...
     if sys.version_info >= (3, 8):
-        def astimezone(self: Self, tz: _TzInfo | None = ...) -> Self: ...
+        def astimezone(self, tz: _TzInfo | None = ...) -> Self: ...
     else:
         def astimezone(self, tz: _TzInfo | None = ...) -> datetime: ...
 
     def isoformat(self, sep: str = ..., timespec: str = ...) -> str: ...
     @classmethod
-    def strptime(cls, __date_string: str, __format: str) -> datetime: ...
+    def strptime(cls, __date_string: str, __format: str) -> Self: ...
     def utcoffset(self) -> timedelta | None: ...
     def tzname(self) -> str | None: ...
     def dst(self) -> timedelta | None: ...
@@ -309,7 +308,7 @@ class datetime(date):
     def __gt__(self, __other: datetime) -> bool: ...  # type: ignore[override]
     if sys.version_info >= (3, 8):
         @overload  # type: ignore[override]
-        def __sub__(self: Self, __other: timedelta) -> Self: ...
+        def __sub__(self, __other: timedelta) -> Self: ...
         @overload
         def __sub__(self: _D, __other: _D) -> timedelta: ...
     else:
diff --git a/mypy/typeshed/stdlib/dbm/__init__.pyi b/mypy/typeshed/stdlib/dbm/__init__.pyi
index ab224086b7be..0068d67b6ad1 100644
--- a/mypy/typeshed/stdlib/dbm/__init__.pyi
+++ b/mypy/typeshed/stdlib/dbm/__init__.pyi
@@ -1,7 +1,6 @@
-from _typeshed import Self
 from collections.abc import Iterator, MutableMapping
 from types import TracebackType
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = ["open", "whichdb", "error"]
 
@@ -82,7 +81,7 @@ class _Database(MutableMapping[_KeyType, bytes]):
     def __iter__(self) -> Iterator[bytes]: ...
     def __len__(self) -> int: ...
     def __del__(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/dbm/dumb.pyi b/mypy/typeshed/stdlib/dbm/dumb.pyi
index d65d163ab568..1fc68cf71f9d 100644
--- a/mypy/typeshed/stdlib/dbm/dumb.pyi
+++ b/mypy/typeshed/stdlib/dbm/dumb.pyi
@@ -1,7 +1,6 @@
-from _typeshed import Self
 from collections.abc import Iterator, MutableMapping
 from types import TracebackType
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 __all__ = ["error", "open"]
 
@@ -24,7 +23,7 @@ class _Database(MutableMapping[_KeyType, bytes]):
     def __iter__(self) -> Iterator[bytes]: ...
     def __len__(self) -> int: ...
     def __del__(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/dbm/gnu.pyi b/mypy/typeshed/stdlib/dbm/gnu.pyi
index adaf6fa8e69b..3dc66a30c370 100644
--- a/mypy/typeshed/stdlib/dbm/gnu.pyi
+++ b/mypy/typeshed/stdlib/dbm/gnu.pyi
@@ -1,8 +1,8 @@
 import sys
-from _typeshed import ReadOnlyBuffer, Self
+from _typeshed import ReadOnlyBuffer
 from types import TracebackType
 from typing import TypeVar, overload
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 if sys.platform != "win32":
     _T = TypeVar("_T")
@@ -24,7 +24,7 @@ if sys.platform != "win32":
         def __delitem__(self, key: _KeyType) -> None: ...
         def __contains__(self, key: _KeyType) -> bool: ...
         def __len__(self) -> int: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(
             self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
         ) -> None: ...
diff --git a/mypy/typeshed/stdlib/dbm/ndbm.pyi b/mypy/typeshed/stdlib/dbm/ndbm.pyi
index ac0b75dfa45b..1106fb2a8e7e 100644
--- a/mypy/typeshed/stdlib/dbm/ndbm.pyi
+++ b/mypy/typeshed/stdlib/dbm/ndbm.pyi
@@ -1,8 +1,8 @@
 import sys
-from _typeshed import ReadOnlyBuffer, Self
+from _typeshed import ReadOnlyBuffer
 from types import TracebackType
 from typing import TypeVar, overload
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 if sys.platform != "win32":
     _T = TypeVar("_T")
@@ -20,7 +20,7 @@ if sys.platform != "win32":
         def __delitem__(self, key: _KeyType) -> None: ...
         def __len__(self) -> int: ...
         def __del__(self) -> None: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(
             self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
         ) -> None: ...
diff --git a/mypy/typeshed/stdlib/dis.pyi b/mypy/typeshed/stdlib/dis.pyi
index ea837f09c806..ac0c5356f5f9 100644
--- a/mypy/typeshed/stdlib/dis.pyi
+++ b/mypy/typeshed/stdlib/dis.pyi
@@ -1,10 +1,9 @@
 import sys
 import types
-from _typeshed import Self
 from collections.abc import Callable, Iterator
 from opcode import *  # `dis` re-exports it as a part of public API
 from typing import IO, Any, NamedTuple
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "code_info",
@@ -82,15 +81,13 @@ class Bytecode:
             adaptive: bool = False,
         ) -> None: ...
         @classmethod
-        def from_traceback(
-            cls: type[Self], tb: types.TracebackType, *, show_caches: bool = False, adaptive: bool = False
-        ) -> Self: ...
+        def from_traceback(cls, tb: types.TracebackType, *, show_caches: bool = False, adaptive: bool = False) -> Self: ...
     else:
         def __init__(
             self, x: _HaveCodeType | str, *, first_line: int | None = None, current_offset: int | None = None
         ) -> None: ...
         @classmethod
-        def from_traceback(cls: type[Self], tb: types.TracebackType) -> Self: ...
+        def from_traceback(cls, tb: types.TracebackType) -> Self: ...
 
     def __iter__(self) -> Iterator[Instruction]: ...
     def info(self) -> str: ...
diff --git a/mypy/typeshed/stdlib/distutils/ccompiler.pyi b/mypy/typeshed/stdlib/distutils/ccompiler.pyi
index 711b30ba4e0e..e7277aa3f9c4 100644
--- a/mypy/typeshed/stdlib/distutils/ccompiler.pyi
+++ b/mypy/typeshed/stdlib/distutils/ccompiler.pyi
@@ -1,8 +1,8 @@
 from collections.abc import Callable
-from typing import Any, Union
+from typing import Any
 from typing_extensions import TypeAlias
 
-_Macro: TypeAlias = Union[tuple[str], tuple[str, str | None]]
+_Macro: TypeAlias = tuple[str] | tuple[str, str | None]
 
 def gen_lib_options(
     compiler: CCompiler, library_dirs: list[str], runtime_library_dirs: list[str], libraries: list[str]
diff --git a/mypy/typeshed/stdlib/distutils/command/check.pyi b/mypy/typeshed/stdlib/distutils/command/check.pyi
index cdbe40fff71d..9cbcc6c87f21 100644
--- a/mypy/typeshed/stdlib/distutils/command/check.pyi
+++ b/mypy/typeshed/stdlib/distutils/command/check.pyi
@@ -6,6 +6,8 @@ from ..cmd import Command
 _Reporter: TypeAlias = Any  # really docutils.utils.Reporter
 
 # Only defined if docutils is installed.
+# Depends on a third-party stub. Since distutils is deprecated anyway,
+# it's easier to just suppress the "any subclassing" error.
 class SilentReporter(_Reporter):
     messages: Any
     def __init__(
diff --git a/mypy/typeshed/stdlib/distutils/version.pyi b/mypy/typeshed/stdlib/distutils/version.pyi
index 4f1b64a7381d..47da65ef87aa 100644
--- a/mypy/typeshed/stdlib/distutils/version.pyi
+++ b/mypy/typeshed/stdlib/distutils/version.pyi
@@ -1,36 +1,36 @@
-from _typeshed import Self
 from abc import abstractmethod
 from re import Pattern
+from typing_extensions import Self
 
 class Version:
     def __eq__(self, other: object) -> bool: ...
-    def __lt__(self: Self, other: Self | str) -> bool: ...
-    def __le__(self: Self, other: Self | str) -> bool: ...
-    def __gt__(self: Self, other: Self | str) -> bool: ...
-    def __ge__(self: Self, other: Self | str) -> bool: ...
+    def __lt__(self, other: Self | str) -> bool: ...
+    def __le__(self, other: Self | str) -> bool: ...
+    def __gt__(self, other: Self | str) -> bool: ...
+    def __ge__(self, other: Self | str) -> bool: ...
     @abstractmethod
     def __init__(self, vstring: str | None = None) -> None: ...
     @abstractmethod
-    def parse(self: Self, vstring: str) -> Self: ...
+    def parse(self, vstring: str) -> Self: ...
     @abstractmethod
     def __str__(self) -> str: ...
     @abstractmethod
-    def _cmp(self: Self, other: Self | str) -> bool: ...
+    def _cmp(self, other: Self | str) -> bool: ...
 
 class StrictVersion(Version):
     version_re: Pattern[str]
     version: tuple[int, int, int]
     prerelease: tuple[str, int] | None
     def __init__(self, vstring: str | None = None) -> None: ...
-    def parse(self: Self, vstring: str) -> Self: ...
+    def parse(self, vstring: str) -> Self: ...
     def __str__(self) -> str: ...  # noqa: Y029
-    def _cmp(self: Self, other: Self | str) -> bool: ...
+    def _cmp(self, other: Self | str) -> bool: ...
 
 class LooseVersion(Version):
     component_re: Pattern[str]
     vstring: str
     version: tuple[str | int, ...]
     def __init__(self, vstring: str | None = None) -> None: ...
-    def parse(self: Self, vstring: str) -> Self: ...
+    def parse(self, vstring: str) -> Self: ...
     def __str__(self) -> str: ...  # noqa: Y029
-    def _cmp(self: Self, other: Self | str) -> bool: ...
+    def _cmp(self, other: Self | str) -> bool: ...
diff --git a/mypy/typeshed/stdlib/email/__init__.pyi b/mypy/typeshed/stdlib/email/__init__.pyi
index 6b59dc73d5cc..fca302f5f1a7 100644
--- a/mypy/typeshed/stdlib/email/__init__.pyi
+++ b/mypy/typeshed/stdlib/email/__init__.pyi
@@ -1,12 +1,12 @@
 from collections.abc import Callable
 from email.message import Message
 from email.policy import Policy
-from typing import IO, Union
+from typing import IO
 from typing_extensions import TypeAlias
 
 # Definitions imported by multiple submodules in typeshed
-_ParamType: TypeAlias = Union[str, tuple[str | None, str | None, str]]  # noqa: Y047
-_ParamsType: TypeAlias = Union[str, None, tuple[str, str | None, str]]  # noqa: Y047
+_ParamType: TypeAlias = str | tuple[str | None, str | None, str]  # noqa: Y047
+_ParamsType: TypeAlias = str | None | tuple[str, str | None, str]  # noqa: Y047
 
 def message_from_string(s: str, _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> Message: ...
 def message_from_bytes(s: bytes | bytearray, _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> Message: ...
diff --git a/mypy/typeshed/stdlib/email/_header_value_parser.pyi b/mypy/typeshed/stdlib/email/_header_value_parser.pyi
index 0e422294e77a..97008140ec5d 100644
--- a/mypy/typeshed/stdlib/email/_header_value_parser.pyi
+++ b/mypy/typeshed/stdlib/email/_header_value_parser.pyi
@@ -1,11 +1,10 @@
 import sys
-from _typeshed import Self
 from collections.abc import Iterable, Iterator
 from email.errors import HeaderParseError, MessageDefect
 from email.policy import Policy
 from re import Pattern
 from typing import Any
-from typing_extensions import Final
+from typing_extensions import Final, Self
 
 WSP: Final[set[str]]
 CFWS_LEADER: Final[set[str]]
@@ -318,7 +317,7 @@ class Terminal(str):
     syntactic_break: bool
     token_type: str
     defects: list[MessageDefect]
-    def __new__(cls: type[Self], value: str, token_type: str) -> Self: ...
+    def __new__(cls, value: str, token_type: str) -> Self: ...
     def pprint(self) -> None: ...
     @property
     def all_defects(self) -> list[MessageDefect]: ...
diff --git a/mypy/typeshed/stdlib/email/headerregistry.pyi b/mypy/typeshed/stdlib/email/headerregistry.pyi
index df07e2458e81..e158e89818f7 100644
--- a/mypy/typeshed/stdlib/email/headerregistry.pyi
+++ b/mypy/typeshed/stdlib/email/headerregistry.pyi
@@ -1,6 +1,5 @@
 import sys
 import types
-from _typeshed import Self
 from collections.abc import Iterable, Mapping
 from datetime import datetime as _datetime
 from email._header_value_parser import (
@@ -15,7 +14,7 @@ from email._header_value_parser import (
 from email.errors import MessageDefect
 from email.policy import Policy
 from typing import Any, ClassVar, Protocol
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 class BaseHeader(str):
     # max_count is actually more of an abstract ClassVar (not defined on the base class, but expected to be defined in subclasses)
@@ -24,7 +23,7 @@ class BaseHeader(str):
     def name(self) -> str: ...
     @property
     def defects(self) -> tuple[MessageDefect, ...]: ...
-    def __new__(cls: type[Self], name: str, value: Any) -> Self: ...
+    def __new__(cls, name: str, value: Any) -> Self: ...
     def init(self, name: str, *, parse_tree: TokenList, defects: Iterable[MessageDefect]) -> None: ...
     def fold(self, *, policy: Policy) -> str: ...
 
diff --git a/mypy/typeshed/stdlib/email/message.pyi b/mypy/typeshed/stdlib/email/message.pyi
index 2777450a77ba..14e018073103 100644
--- a/mypy/typeshed/stdlib/email/message.pyi
+++ b/mypy/typeshed/stdlib/email/message.pyi
@@ -1,4 +1,3 @@
-from _typeshed import Self
 from collections.abc import Generator, Iterator, Sequence
 from email import _ParamsType, _ParamType
 from email.charset import Charset
@@ -6,7 +5,7 @@ from email.contentmanager import ContentManager
 from email.errors import MessageDefect
 from email.policy import Policy
 from typing import Any, TypeVar, overload
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 __all__ = ["Message", "EmailMessage"]
 
@@ -84,7 +83,7 @@ class Message:
     def get_charsets(self, failobj: None = None) -> list[str] | None: ...
     @overload
     def get_charsets(self, failobj: _T) -> list[str] | _T: ...
-    def walk(self: Self) -> Generator[Self, None, None]: ...
+    def walk(self) -> Generator[Self, None, None]: ...
     def get_content_disposition(self) -> str | None: ...
     def as_string(self, unixfrom: bool = False, maxheaderlen: int = 0, policy: Policy | None = None) -> str: ...
     def as_bytes(self, unixfrom: bool = False, policy: Policy | None = None) -> bytes: ...
diff --git a/mypy/typeshed/stdlib/email/parser.pyi b/mypy/typeshed/stdlib/email/parser.pyi
index ba5dace28916..28b6aca856ca 100644
--- a/mypy/typeshed/stdlib/email/parser.pyi
+++ b/mypy/typeshed/stdlib/email/parser.pyi
@@ -1,25 +1,26 @@
+from _typeshed import SupportsRead
 from collections.abc import Callable
 from email.feedparser import BytesFeedParser as BytesFeedParser, FeedParser as FeedParser
 from email.message import Message
 from email.policy import Policy
-from typing import BinaryIO, TextIO
+from typing import IO
 
 __all__ = ["Parser", "HeaderParser", "BytesParser", "BytesHeaderParser", "FeedParser", "BytesFeedParser"]
 
 class Parser:
     def __init__(self, _class: Callable[[], Message] | None = None, *, policy: Policy = ...) -> None: ...
-    def parse(self, fp: TextIO, headersonly: bool = False) -> Message: ...
+    def parse(self, fp: SupportsRead[str], headersonly: bool = False) -> Message: ...
     def parsestr(self, text: str, headersonly: bool = False) -> Message: ...
 
 class HeaderParser(Parser):
-    def parse(self, fp: TextIO, headersonly: bool = True) -> Message: ...
+    def parse(self, fp: SupportsRead[str], headersonly: bool = True) -> Message: ...
     def parsestr(self, text: str, headersonly: bool = True) -> Message: ...
 
 class BytesParser:
     def __init__(self, _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> None: ...
-    def parse(self, fp: BinaryIO, headersonly: bool = False) -> Message: ...
+    def parse(self, fp: IO[bytes], headersonly: bool = False) -> Message: ...
     def parsebytes(self, text: bytes | bytearray, headersonly: bool = False) -> Message: ...
 
 class BytesHeaderParser(BytesParser):
-    def parse(self, fp: BinaryIO, headersonly: bool = True) -> Message: ...
+    def parse(self, fp: IO[bytes], headersonly: bool = True) -> Message: ...
     def parsebytes(self, text: bytes | bytearray, headersonly: bool = True) -> Message: ...
diff --git a/mypy/typeshed/stdlib/enum.pyi b/mypy/typeshed/stdlib/enum.pyi
index 182076731ab2..b46fe429cacb 100644
--- a/mypy/typeshed/stdlib/enum.pyi
+++ b/mypy/typeshed/stdlib/enum.pyi
@@ -1,11 +1,12 @@
+import _typeshed
 import sys
 import types
-from _typeshed import Self, SupportsKeysAndGetItem, Unused
+from _typeshed import SupportsKeysAndGetItem, Unused
 from abc import ABCMeta
 from builtins import property as _builtins_property
 from collections.abc import Iterable, Iterator, Mapping
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = ["EnumMeta", "Enum", "IntEnum", "Flag", "IntFlag", "auto", "unique"]
 
@@ -80,7 +81,7 @@ class _EnumDict(dict[str, Any]):
 class EnumMeta(ABCMeta):
     if sys.version_info >= (3, 11):
         def __new__(
-            metacls: type[Self],
+            metacls: type[_typeshed.Self],
             cls: str,
             bases: tuple[type, ...],
             classdict: _EnumDict,
@@ -88,11 +89,13 @@ class EnumMeta(ABCMeta):
             boundary: FlagBoundary | None = None,
             _simple: bool = False,
             **kwds: Any,
-        ) -> Self: ...
+        ) -> _typeshed.Self: ...
     elif sys.version_info >= (3, 9):
-        def __new__(metacls: type[Self], cls: str, bases: tuple[type, ...], classdict: _EnumDict, **kwds: Any) -> Self: ...
+        def __new__(
+            metacls: type[_typeshed.Self], cls: str, bases: tuple[type, ...], classdict: _EnumDict, **kwds: Any
+        ) -> _typeshed.Self: ...
     else:
-        def __new__(metacls: type[Self], cls: str, bases: tuple[type, ...], classdict: _EnumDict) -> Self: ...
+        def __new__(metacls: type[_typeshed.Self], cls: str, bases: tuple[type, ...], classdict: _EnumDict) -> _typeshed.Self: ...
 
     if sys.version_info >= (3, 9):
         @classmethod
@@ -174,7 +177,7 @@ class Enum(metaclass=EnumMeta):
     # However, using `Any` causes too many false-positives for those using mypy's `--disallow-any-expr`
     # (see #7752, #2539, mypy/#5788),
     # and in practice using `object` here has the same effect as using `Any`.
-    def __new__(cls: type[Self], value: object) -> Self: ...
+    def __new__(cls, value: object) -> Self: ...
     def __dir__(self) -> list[str]: ...
     def __format__(self, format_spec: str) -> str: ...
     def __reduce_ex__(self, proto: Unused) -> tuple[Any, ...]: ...
@@ -191,7 +194,7 @@ class IntEnum(int, _IntEnumBase):
     _value_: int
     @_magic_enum_attr
     def value(self) -> int: ...
-    def __new__(cls: type[Self], value: int) -> Self: ...
+    def __new__(cls, value: int) -> Self: ...
 
 def unique(enumeration: _EnumerationT) -> _EnumerationT: ...
 
@@ -202,7 +205,7 @@ class auto(IntFlag):
     _value_: Any
     @_magic_enum_attr
     def value(self) -> Any: ...
-    def __new__(cls: type[Self]) -> Self: ...
+    def __new__(cls) -> Self: ...
 
 class Flag(Enum):
     _name_: str | None  # type: ignore[assignment]
@@ -211,14 +214,14 @@ class Flag(Enum):
     def name(self) -> str | None: ...  # type: ignore[override]
     @_magic_enum_attr
     def value(self) -> int: ...
-    def __contains__(self: Self, other: Self) -> bool: ...
+    def __contains__(self, other: Self) -> bool: ...
     def __bool__(self) -> bool: ...
-    def __or__(self: Self, other: Self) -> Self: ...
-    def __and__(self: Self, other: Self) -> Self: ...
-    def __xor__(self: Self, other: Self) -> Self: ...
-    def __invert__(self: Self) -> Self: ...
+    def __or__(self, other: Self) -> Self: ...
+    def __and__(self, other: Self) -> Self: ...
+    def __xor__(self, other: Self) -> Self: ...
+    def __invert__(self) -> Self: ...
     if sys.version_info >= (3, 11):
-        def __iter__(self: Self) -> Iterator[Self]: ...
+        def __iter__(self) -> Iterator[Self]: ...
         def __len__(self) -> int: ...
         __ror__ = __or__
         __rand__ = __and__
@@ -226,28 +229,28 @@ class Flag(Enum):
 
 if sys.version_info >= (3, 11):
     # The body of the class is the same, but the base classes are different.
-    class IntFlag(int, ReprEnum, Flag, boundary=KEEP):
-        def __new__(cls: type[Self], value: int) -> Self: ...
-        def __or__(self: Self, other: int) -> Self: ...
-        def __and__(self: Self, other: int) -> Self: ...
-        def __xor__(self: Self, other: int) -> Self: ...
+    class IntFlag(int, ReprEnum, Flag, boundary=KEEP):  # type: ignore[misc]  # complaints about incompatible bases
+        def __new__(cls, value: int) -> Self: ...
+        def __or__(self, other: int) -> Self: ...
+        def __and__(self, other: int) -> Self: ...
+        def __xor__(self, other: int) -> Self: ...
         __ror__ = __or__
         __rand__ = __and__
         __rxor__ = __xor__
 
 else:
-    class IntFlag(int, Flag):
-        def __new__(cls: type[Self], value: int) -> Self: ...
-        def __or__(self: Self, other: int) -> Self: ...
-        def __and__(self: Self, other: int) -> Self: ...
-        def __xor__(self: Self, other: int) -> Self: ...
+    class IntFlag(int, Flag):  # type: ignore[misc]  # complaints about incompatible bases
+        def __new__(cls, value: int) -> Self: ...
+        def __or__(self, other: int) -> Self: ...
+        def __and__(self, other: int) -> Self: ...
+        def __xor__(self, other: int) -> Self: ...
         __ror__ = __or__
         __rand__ = __and__
         __rxor__ = __xor__
 
 if sys.version_info >= (3, 11):
     class StrEnum(str, ReprEnum):
-        def __new__(cls: type[Self], value: str) -> Self: ...
+        def __new__(cls, value: str) -> Self: ...
         _value_: str
         @_magic_enum_attr
         def value(self) -> str: ...
diff --git a/mypy/typeshed/stdlib/fileinput.pyi b/mypy/typeshed/stdlib/fileinput.pyi
index 17379e92ba5f..e9f3713b4eaf 100644
--- a/mypy/typeshed/stdlib/fileinput.pyi
+++ b/mypy/typeshed/stdlib/fileinput.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import AnyStr_co, Self, StrOrBytesPath
+from _typeshed import AnyStr_co, StrOrBytesPath
 from collections.abc import Callable, Iterable, Iterator
 from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, Protocol, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -289,11 +289,11 @@ class FileInput(Iterator[AnyStr], Generic[AnyStr]):
 
     def __del__(self) -> None: ...
     def close(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> AnyStr: ...
     if sys.version_info < (3, 11):
         def __getitem__(self, i: int) -> AnyStr: ...
diff --git a/mypy/typeshed/stdlib/fractions.pyi b/mypy/typeshed/stdlib/fractions.pyi
index 95e4aad0f9ca..97cefc916d9b 100644
--- a/mypy/typeshed/stdlib/fractions.pyi
+++ b/mypy/typeshed/stdlib/fractions.pyi
@@ -1,10 +1,9 @@
 import sys
-from _typeshed import Self
 from collections.abc import Callable
 from decimal import Decimal
 from numbers import Integral, Rational, Real
 from typing import Any, overload
-from typing_extensions import Literal, SupportsIndex, TypeAlias
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias
 
 _ComparableNum: TypeAlias = int | float | Decimal | Real
 
@@ -24,14 +23,14 @@ else:
 class Fraction(Rational):
     @overload
     def __new__(
-        cls: type[Self], numerator: int | Rational = 0, denominator: int | Rational | None = None, *, _normalize: bool = True
+        cls, numerator: int | Rational = 0, denominator: int | Rational | None = None, *, _normalize: bool = True
     ) -> Self: ...
     @overload
-    def __new__(cls: type[Self], __value: float | Decimal | str, *, _normalize: bool = True) -> Self: ...
+    def __new__(cls, __value: float | Decimal | str, *, _normalize: bool = True) -> Self: ...
     @classmethod
-    def from_float(cls: type[Self], f: float) -> Self: ...
+    def from_float(cls, f: float) -> Self: ...
     @classmethod
-    def from_decimal(cls: type[Self], dec: Decimal) -> Self: ...
+    def from_decimal(cls, dec: Decimal) -> Self: ...
     def limit_denominator(self, max_denominator: int = 1000000) -> Fraction: ...
     if sys.version_info >= (3, 8):
         def as_integer_ratio(self) -> tuple[int, int]: ...
@@ -139,8 +138,8 @@ class Fraction(Rational):
     def __le__(a, b: _ComparableNum) -> bool: ...
     def __ge__(a, b: _ComparableNum) -> bool: ...
     def __bool__(a) -> bool: ...
-    def __copy__(self: Self) -> Self: ...
-    def __deepcopy__(self: Self, memo: Any) -> Self: ...
+    def __copy__(self) -> Self: ...
+    def __deepcopy__(self, memo: Any) -> Self: ...
     if sys.version_info >= (3, 11):
         def __int__(a, _index: Callable[[SupportsIndex], int] = ...) -> int: ...
     # Not actually defined within fractions.py, but provides more useful
diff --git a/mypy/typeshed/stdlib/ftplib.pyi b/mypy/typeshed/stdlib/ftplib.pyi
index 6c33f1409822..76d9dc02a5da 100644
--- a/mypy/typeshed/stdlib/ftplib.pyi
+++ b/mypy/typeshed/stdlib/ftplib.pyi
@@ -1,11 +1,11 @@
 import sys
-from _typeshed import Self, SupportsRead, SupportsReadline
+from _typeshed import SupportsRead, SupportsReadline
 from collections.abc import Callable, Iterable, Iterator
 from socket import socket
 from ssl import SSLContext
 from types import TracebackType
 from typing import Any, TextIO
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 __all__ = ["FTP", "error_reply", "error_temp", "error_perm", "error_proto", "all_errors", "FTP_TLS"]
 
@@ -36,7 +36,7 @@ class FTP:
     lastresp: str
     file: TextIO | None
     encoding: str
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/functools.pyi b/mypy/typeshed/stdlib/functools.pyi
index 8778798144de..1214e349f605 100644
--- a/mypy/typeshed/stdlib/functools.pyi
+++ b/mypy/typeshed/stdlib/functools.pyi
@@ -1,9 +1,9 @@
 import sys
 import types
-from _typeshed import IdentityFunction, Self, SupportsAllComparisons, SupportsItems
+from _typeshed import IdentityFunction, SupportsAllComparisons, SupportsItems
 from collections.abc import Callable, Hashable, Iterable, Sequence, Sized
 from typing import Any, Generic, NamedTuple, TypeVar, overload
-from typing_extensions import Literal, TypeAlias, final
+from typing_extensions import Literal, Self, TypeAlias, final
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -79,7 +79,7 @@ class partial(Generic[_T]):
     def args(self) -> tuple[Any, ...]: ...
     @property
     def keywords(self) -> dict[str, Any]: ...
-    def __new__(cls: type[Self], __func: Callable[..., _T], *args: Any, **kwargs: Any) -> Self: ...
+    def __new__(cls, __func: Callable[..., _T], *args: Any, **kwargs: Any) -> Self: ...
     def __call__(__self, *args: Any, **kwargs: Any) -> _T: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
@@ -111,11 +111,11 @@ class _SingleDispatchCallable(Generic[_T]):
     # @fun.register(complex)
     # def _(arg, verbose=False): ...
     @overload
-    def register(self, cls: type[Any], func: None = ...) -> Callable[[Callable[..., _T]], Callable[..., _T]]: ...
+    def register(self, cls: type[Any], func: None = None) -> Callable[[Callable[..., _T]], Callable[..., _T]]: ...
     # @fun.register
     # def _(arg: int, verbose=False):
     @overload
-    def register(self, cls: Callable[..., _T], func: None = ...) -> Callable[..., _T]: ...
+    def register(self, cls: Callable[..., _T], func: None = None) -> Callable[..., _T]: ...
     # fun.register(int, lambda x: x)
     @overload
     def register(self, cls: type[Any], func: Callable[..., _T]) -> Callable[..., _T]: ...
diff --git a/mypy/typeshed/stdlib/hashlib.pyi b/mypy/typeshed/stdlib/hashlib.pyi
index 8292e319330a..18b1ab549764 100644
--- a/mypy/typeshed/stdlib/hashlib.pyi
+++ b/mypy/typeshed/stdlib/hashlib.pyi
@@ -1,8 +1,8 @@
 import sys
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from collections.abc import Callable, Set as AbstractSet
 from typing import Protocol
-from typing_extensions import final
+from typing_extensions import Self, final
 
 if sys.version_info >= (3, 11):
     __all__ = (
@@ -56,7 +56,7 @@ class _Hash:
     @property
     def name(self) -> str: ...
     def __init__(self, data: ReadableBuffer = ...) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def digest(self) -> bytes: ...
     def hexdigest(self) -> str: ...
     def update(self, __data: ReadableBuffer) -> None: ...
diff --git a/mypy/typeshed/stdlib/heapq.pyi b/mypy/typeshed/stdlib/heapq.pyi
index 9d7815507ea5..61418b3704d6 100644
--- a/mypy/typeshed/stdlib/heapq.pyi
+++ b/mypy/typeshed/stdlib/heapq.pyi
@@ -2,12 +2,13 @@ from _heapq import *
 from _typeshed import SupportsRichComparison
 from collections.abc import Callable, Iterable
 from typing import Any, TypeVar
+from typing_extensions import Final
 
 __all__ = ["heappush", "heappop", "heapify", "heapreplace", "merge", "nlargest", "nsmallest", "heappushpop"]
 
 _S = TypeVar("_S")
 
-__about__: str
+__about__: Final[str]
 
 def merge(
     *iterables: Iterable[_S], key: Callable[[_S], SupportsRichComparison] | None = None, reverse: bool = False
diff --git a/mypy/typeshed/stdlib/http/client.pyi b/mypy/typeshed/stdlib/http/client.pyi
index bb641875e55b..b1506b50e750 100644
--- a/mypy/typeshed/stdlib/http/client.pyi
+++ b/mypy/typeshed/stdlib/http/client.pyi
@@ -2,11 +2,11 @@ import email.message
 import io
 import ssl
 import types
-from _typeshed import ReadableBuffer, Self, SupportsRead, WriteableBuffer
+from _typeshed import ReadableBuffer, SupportsRead, WriteableBuffer
 from collections.abc import Callable, Iterable, Iterator, Mapping
 from socket import socket
 from typing import Any, BinaryIO, TypeVar, overload
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "HTTPResponse",
@@ -127,7 +127,7 @@ class HTTPResponse(io.BufferedIOBase, BinaryIO):
     def getheaders(self) -> list[tuple[str, str]]: ...
     def isclosed(self) -> bool: ...
     def __iter__(self) -> Iterator[bytes]: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: types.TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/imaplib.pyi b/mypy/typeshed/stdlib/imaplib.pyi
index 8016d8bec5cd..1c2112dd37c8 100644
--- a/mypy/typeshed/stdlib/imaplib.pyi
+++ b/mypy/typeshed/stdlib/imaplib.pyi
@@ -1,7 +1,7 @@
 import subprocess
 import sys
 import time
-from _typeshed import ReadableBuffer, Self, _BufferWithLen
+from _typeshed import ReadableBuffer, _BufferWithLen
 from builtins import list as _list  # conflicts with a method named "list"
 from collections.abc import Callable
 from datetime import datetime
@@ -10,7 +10,7 @@ from socket import socket as _socket
 from ssl import SSLContext, SSLSocket
 from types import TracebackType
 from typing import IO, Any, SupportsAbs, SupportsInt
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = ["IMAP4", "IMAP4_stream", "Internaldate2tuple", "Int2AP", "ParseFlags", "Time2Internaldate", "IMAP4_SSL"]
 
@@ -69,7 +69,7 @@ class IMAP4:
     def delete(self, mailbox: str) -> _CommandResults: ...
     def deleteacl(self, mailbox: str, who: str) -> _CommandResults: ...
     def enable(self, capability: str) -> _CommandResults: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
     def expunge(self) -> _CommandResults: ...
     def fetch(self, message_set: str, message_parts: str) -> tuple[str, _AnyResponseData]: ...
diff --git a/mypy/typeshed/stdlib/importlib/abc.pyi b/mypy/typeshed/stdlib/importlib/abc.pyi
index 78b79267d06e..3d0c2d38c4e9 100644
--- a/mypy/typeshed/stdlib/importlib/abc.pyi
+++ b/mypy/typeshed/stdlib/importlib/abc.pyi
@@ -133,7 +133,7 @@ if sys.version_info >= (3, 9):
         @overload
         @abstractmethod
         def open(
-            self, mode: OpenBinaryMode, buffering: Literal[0], encoding: None = ..., errors: None = ..., newline: None = ...
+            self, mode: OpenBinaryMode, buffering: Literal[0], encoding: None = None, errors: None = None, newline: None = None
         ) -> FileIO: ...
         # Buffering is on: return BufferedRandom, BufferedReader, or BufferedWriter
         @overload
@@ -142,9 +142,9 @@ if sys.version_info >= (3, 9):
             self,
             mode: OpenBinaryModeUpdating,
             buffering: Literal[-1, 1] = ...,
-            encoding: None = ...,
-            errors: None = ...,
-            newline: None = ...,
+            encoding: None = None,
+            errors: None = None,
+            newline: None = None,
         ) -> BufferedRandom: ...
         @overload
         @abstractmethod
@@ -152,9 +152,9 @@ if sys.version_info >= (3, 9):
             self,
             mode: OpenBinaryModeWriting,
             buffering: Literal[-1, 1] = ...,
-            encoding: None = ...,
-            errors: None = ...,
-            newline: None = ...,
+            encoding: None = None,
+            errors: None = None,
+            newline: None = None,
         ) -> BufferedWriter: ...
         @overload
         @abstractmethod
@@ -162,15 +162,15 @@ if sys.version_info >= (3, 9):
             self,
             mode: OpenBinaryModeReading,
             buffering: Literal[-1, 1] = ...,
-            encoding: None = ...,
-            errors: None = ...,
-            newline: None = ...,
+            encoding: None = None,
+            errors: None = None,
+            newline: None = None,
         ) -> BufferedReader: ...
         # Buffering cannot be determined: fall back to BinaryIO
         @overload
         @abstractmethod
         def open(
-            self, mode: OpenBinaryMode, buffering: int = ..., encoding: None = ..., errors: None = ..., newline: None = ...
+            self, mode: OpenBinaryMode, buffering: int = ..., encoding: None = None, errors: None = None, newline: None = None
         ) -> BinaryIO: ...
         # Fallback if mode is not specified
         @overload
diff --git a/mypy/typeshed/stdlib/importlib/metadata/__init__.pyi b/mypy/typeshed/stdlib/importlib/metadata/__init__.pyi
index cc93aaeca365..083453cd3c9a 100644
--- a/mypy/typeshed/stdlib/importlib/metadata/__init__.pyi
+++ b/mypy/typeshed/stdlib/importlib/metadata/__init__.pyi
@@ -1,7 +1,7 @@
 import abc
 import pathlib
 import sys
-from _typeshed import Self, StrPath
+from _typeshed import StrPath
 from collections.abc import Iterable, Mapping
 from email.message import Message
 from importlib.abc import MetaPathFinder
@@ -9,6 +9,7 @@ from os import PathLike
 from pathlib import Path
 from re import Pattern
 from typing import Any, ClassVar, NamedTuple, overload
+from typing_extensions import Self
 
 __all__ = [
     "Distribution",
@@ -86,13 +87,13 @@ if sys.version_info >= (3, 10):
 
     class SelectableGroups(dict[str, EntryPoints]):  # use as dict is deprecated since 3.10
         @classmethod
-        def load(cls: type[Self], eps: Iterable[EntryPoint]) -> Self: ...
+        def load(cls, eps: Iterable[EntryPoint]) -> Self: ...
         @property
         def groups(self) -> set[str]: ...
         @property
         def names(self) -> set[str]: ...
         @overload
-        def select(self: Self) -> Self: ...  # type: ignore[misc]
+        def select(self) -> Self: ...  # type: ignore[misc]
         @overload
         def select(
             self,
@@ -132,7 +133,7 @@ class Distribution:
     @overload
     @classmethod
     def discover(
-        cls, *, context: None = ..., name: str | None = ..., path: list[str] = ..., **kwargs: Any
+        cls, *, context: None = None, name: str | None = ..., path: list[str] = ..., **kwargs: Any
     ) -> Iterable[Distribution]: ...
     @staticmethod
     def at(path: StrPath) -> PathDistribution: ...
@@ -185,7 +186,7 @@ def distribution(distribution_name: str) -> Distribution: ...
 def distributions(*, context: DistributionFinder.Context) -> Iterable[Distribution]: ...
 @overload
 def distributions(
-    *, context: None = ..., name: str | None = ..., path: list[str] = ..., **kwargs: Any
+    *, context: None = None, name: str | None = ..., path: list[str] = ..., **kwargs: Any
 ) -> Iterable[Distribution]: ...
 
 if sys.version_info >= (3, 10):
diff --git a/mypy/typeshed/stdlib/inspect.pyi b/mypy/typeshed/stdlib/inspect.pyi
index 3b82e0b0af2a..2525ef4968ec 100644
--- a/mypy/typeshed/stdlib/inspect.pyi
+++ b/mypy/typeshed/stdlib/inspect.pyi
@@ -2,7 +2,6 @@ import dis
 import enum
 import sys
 import types
-from _typeshed import Self
 from collections import OrderedDict
 from collections.abc import AsyncGenerator, Awaitable, Callable, Coroutine, Generator, Mapping, Sequence, Set as AbstractSet
 from types import (
@@ -25,8 +24,8 @@ from types import (
     TracebackType,
     WrapperDescriptorType,
 )
-from typing import Any, ClassVar, NamedTuple, Protocol, TypeVar, Union, overload
-from typing_extensions import Literal, ParamSpec, TypeAlias, TypeGuard
+from typing import Any, ClassVar, NamedTuple, Protocol, TypeVar, overload
+from typing_extensions import Literal, ParamSpec, Self, TypeAlias, TypeGuard
 
 if sys.version_info >= (3, 11):
     __all__ = [
@@ -264,9 +263,9 @@ def isdatadescriptor(object: object) -> TypeGuard[_SupportsSet[Any, Any] | _Supp
 #
 # Retrieving source code
 #
-_SourceObjectType: TypeAlias = Union[
-    ModuleType, type[Any], MethodType, FunctionType, TracebackType, FrameType, CodeType, Callable[..., Any]
-]
+_SourceObjectType: TypeAlias = (
+    ModuleType | type[Any] | MethodType | FunctionType | TracebackType | FrameType | CodeType | Callable[..., Any]
+)
 
 def findsource(object: _SourceObjectType) -> tuple[list[str], int]: ...
 def getabsfile(object: _SourceObjectType, _filename: str | None = None) -> str: ...
@@ -313,13 +312,11 @@ class Signature:
     def return_annotation(self) -> Any: ...
     def bind(self, *args: Any, **kwargs: Any) -> BoundArguments: ...
     def bind_partial(self, *args: Any, **kwargs: Any) -> BoundArguments: ...
-    def replace(
-        self: Self, *, parameters: Sequence[Parameter] | type[_void] | None = ..., return_annotation: Any = ...
-    ) -> Self: ...
+    def replace(self, *, parameters: Sequence[Parameter] | type[_void] | None = ..., return_annotation: Any = ...) -> Self: ...
     if sys.version_info >= (3, 10):
         @classmethod
         def from_callable(
-            cls: type[Self],
+            cls,
             obj: _IntrospectableCallable,
             *,
             follow_wrapped: bool = True,
@@ -329,7 +326,7 @@ class Signature:
         ) -> Self: ...
     else:
         @classmethod
-        def from_callable(cls: type[Self], obj: _IntrospectableCallable, *, follow_wrapped: bool = True) -> Self: ...
+        def from_callable(cls, obj: _IntrospectableCallable, *, follow_wrapped: bool = True) -> Self: ...
 
     def __eq__(self, other: object) -> bool: ...
 
@@ -372,7 +369,7 @@ class Parameter:
     @property
     def annotation(self) -> Any: ...
     def replace(
-        self: Self,
+        self,
         *,
         name: str | type[_void] = ...,
         kind: _ParameterKind | type[_void] = ...,
@@ -493,7 +490,7 @@ if sys.version_info >= (3, 11):
     class Traceback(_Traceback):
         positions: dis.Positions | None
         def __new__(
-            cls: type[Self],
+            cls,
             filename: str,
             lineno: int,
             function: str,
@@ -514,7 +511,7 @@ if sys.version_info >= (3, 11):
     class FrameInfo(_FrameInfo):
         positions: dis.Positions | None
         def __new__(
-            cls: type[Self],
+            cls,
             frame: FrameType,
             filename: str,
             lineno: int,
diff --git a/mypy/typeshed/stdlib/io.pyi b/mypy/typeshed/stdlib/io.pyi
index 6e1b4be77b07..c3e07bacbe5a 100644
--- a/mypy/typeshed/stdlib/io.pyi
+++ b/mypy/typeshed/stdlib/io.pyi
@@ -2,12 +2,12 @@ import abc
 import builtins
 import codecs
 import sys
-from _typeshed import FileDescriptorOrPath, ReadableBuffer, Self, WriteableBuffer
+from _typeshed import FileDescriptorOrPath, ReadableBuffer, WriteableBuffer
 from collections.abc import Callable, Iterable, Iterator
 from os import _Opener
 from types import TracebackType
 from typing import IO, Any, BinaryIO, TextIO
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 __all__ = [
     "BlockingIOError",
@@ -51,7 +51,7 @@ class UnsupportedOperation(OSError, ValueError): ...
 class IOBase(metaclass=abc.ABCMeta):
     def __iter__(self) -> Iterator[bytes]: ...
     def __next__(self) -> bytes: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
@@ -100,7 +100,7 @@ class FileIO(RawIOBase, BinaryIO):
     def closefd(self) -> bool: ...
     def write(self, __b: ReadableBuffer) -> int: ...
     def read(self, __size: int = -1) -> bytes: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
 
 class BytesIO(BufferedIOBase, BinaryIO):
     def __init__(self, initial_bytes: ReadableBuffer = ...) -> None: ...
@@ -108,23 +108,23 @@ class BytesIO(BufferedIOBase, BinaryIO):
     # to allow BytesIO sub-classes to add this field, as it is defined
     # as a read-only property on IO[].
     name: Any
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def getvalue(self) -> bytes: ...
     def getbuffer(self) -> memoryview: ...
     def read1(self, __size: int | None = -1) -> bytes: ...
 
 class BufferedReader(BufferedIOBase, BinaryIO):
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __init__(self, raw: RawIOBase, buffer_size: int = ...) -> None: ...
     def peek(self, __size: int = 0) -> bytes: ...
 
 class BufferedWriter(BufferedIOBase, BinaryIO):
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __init__(self, raw: RawIOBase, buffer_size: int = ...) -> None: ...
     def write(self, __buffer: ReadableBuffer) -> int: ...
 
 class BufferedRandom(BufferedReader, BufferedWriter):
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def seek(self, __target: int, __whence: int = 0) -> int: ...  # stubtest needs this
 
 class BufferedRWPair(BufferedIOBase):
@@ -172,7 +172,7 @@ class TextIOWrapper(TextIOBase, TextIO):
         write_through: bool | None = None,
     ) -> None: ...
     # These are inherited from TextIOBase, but must exist in the stub to satisfy mypy.
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __iter__(self) -> Iterator[str]: ...  # type: ignore[override]
     def __next__(self) -> str: ...  # type: ignore[override]
     def writelines(self, __lines: Iterable[str]) -> None: ...  # type: ignore[override]
diff --git a/mypy/typeshed/stdlib/ipaddress.pyi b/mypy/typeshed/stdlib/ipaddress.pyi
index 1de945db5d30..9f9662137765 100644
--- a/mypy/typeshed/stdlib/ipaddress.pyi
+++ b/mypy/typeshed/stdlib/ipaddress.pyi
@@ -1,8 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Container, Iterable, Iterator
 from typing import Any, Generic, SupportsInt, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 # Undocumented length constants
 IPV4LENGTH: Literal[32]
@@ -34,20 +33,20 @@ class _IPAddressBase:
 
 class _BaseAddress(_IPAddressBase, SupportsInt):
     def __init__(self, address: object) -> None: ...
-    def __add__(self: Self, other: int) -> Self: ...
+    def __add__(self, other: int) -> Self: ...
     def __int__(self) -> int: ...
-    def __sub__(self: Self, other: int) -> Self: ...
+    def __sub__(self, other: int) -> Self: ...
     def __format__(self, fmt: str) -> str: ...
     def __eq__(self, other: object) -> bool: ...
-    def __lt__(self: Self, other: Self) -> bool: ...
+    def __lt__(self, other: Self) -> bool: ...
     if sys.version_info >= (3, 11):
-        def __ge__(self: Self, other: Self) -> bool: ...
-        def __gt__(self: Self, other: Self) -> bool: ...
-        def __le__(self: Self, other: Self) -> bool: ...
+        def __ge__(self, other: Self) -> bool: ...
+        def __gt__(self, other: Self) -> bool: ...
+        def __le__(self, other: Self) -> bool: ...
     else:
-        def __ge__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
-        def __gt__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
-        def __le__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __ge__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __gt__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __le__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
 
     @property
     def is_global(self) -> bool: ...
@@ -76,20 +75,20 @@ class _BaseNetwork(_IPAddressBase, Container[_A], Iterable[_A], Generic[_A]):
     def __getitem__(self, n: int) -> _A: ...
     def __iter__(self) -> Iterator[_A]: ...
     def __eq__(self, other: object) -> bool: ...
-    def __lt__(self: Self, other: Self) -> bool: ...
+    def __lt__(self, other: Self) -> bool: ...
     if sys.version_info >= (3, 11):
-        def __ge__(self: Self, other: Self) -> bool: ...
-        def __gt__(self: Self, other: Self) -> bool: ...
-        def __le__(self: Self, other: Self) -> bool: ...
+        def __ge__(self, other: Self) -> bool: ...
+        def __gt__(self, other: Self) -> bool: ...
+        def __le__(self, other: Self) -> bool: ...
     else:
-        def __ge__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
-        def __gt__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
-        def __le__(self: Self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __ge__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __gt__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
+        def __le__(self, other: Self, NotImplemented: Any = ...) -> bool: ...
 
-    def address_exclude(self: Self, other: Self) -> Iterator[Self]: ...
+    def address_exclude(self, other: Self) -> Iterator[Self]: ...
     @property
     def broadcast_address(self) -> _A: ...
-    def compare_networks(self: Self, other: Self) -> int: ...
+    def compare_networks(self, other: Self) -> int: ...
     def hosts(self) -> Iterator[_A]: ...
     @property
     def is_global(self) -> bool: ...
@@ -112,10 +111,10 @@ class _BaseNetwork(_IPAddressBase, Container[_A], Iterable[_A], Generic[_A]):
     def overlaps(self, other: _BaseNetwork[IPv4Address] | _BaseNetwork[IPv6Address]) -> bool: ...
     @property
     def prefixlen(self) -> int: ...
-    def subnet_of(self: Self, other: Self) -> bool: ...
-    def supernet_of(self: Self, other: Self) -> bool: ...
-    def subnets(self: Self, prefixlen_diff: int = 1, new_prefix: int | None = None) -> Iterator[Self]: ...
-    def supernet(self: Self, prefixlen_diff: int = 1, new_prefix: int | None = None) -> Self: ...
+    def subnet_of(self, other: Self) -> bool: ...
+    def supernet_of(self, other: Self) -> bool: ...
+    def subnets(self, prefixlen_diff: int = 1, new_prefix: int | None = None) -> Iterator[Self]: ...
+    def supernet(self, prefixlen_diff: int = 1, new_prefix: int | None = None) -> Self: ...
     @property
     def with_hostmask(self) -> str: ...
     @property
diff --git a/mypy/typeshed/stdlib/itertools.pyi b/mypy/typeshed/stdlib/itertools.pyi
index a16827a3adb8..c7b92c3aebb5 100644
--- a/mypy/typeshed/stdlib/itertools.pyi
+++ b/mypy/typeshed/stdlib/itertools.pyi
@@ -1,8 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Callable, Iterable, Iterator
 from typing import Any, Generic, SupportsComplex, SupportsFloat, SupportsInt, TypeVar, overload
-from typing_extensions import Literal, SupportsIndex, TypeAlias
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -32,12 +31,12 @@ class count(Iterator[_N], Generic[_N]):
     @overload
     def __new__(cls, *, step: _N) -> count[_N]: ...
     def __next__(self) -> _N: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
 
 class cycle(Iterator[_T], Generic[_T]):
     def __init__(self, __iterable: Iterable[_T]) -> None: ...
     def __next__(self) -> _T: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
 
 class repeat(Iterator[_T], Generic[_T]):
     @overload
@@ -45,25 +44,25 @@ class repeat(Iterator[_T], Generic[_T]):
     @overload
     def __init__(self, object: _T, times: int) -> None: ...
     def __next__(self) -> _T: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __length_hint__(self) -> int: ...
 
 class accumulate(Iterator[_T], Generic[_T]):
     if sys.version_info >= (3, 8):
         @overload
-        def __init__(self, iterable: Iterable[_T], func: None = ..., *, initial: _T | None = ...) -> None: ...
+        def __init__(self, iterable: Iterable[_T], func: None = None, *, initial: _T | None = ...) -> None: ...
         @overload
         def __init__(self, iterable: Iterable[_S], func: Callable[[_T, _S], _T], *, initial: _T | None = ...) -> None: ...
     else:
         def __init__(self, iterable: Iterable[_T], func: Callable[[_T, _T], _T] | None = ...) -> None: ...
 
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class chain(Iterator[_T], Generic[_T]):
     def __init__(self, *iterables: Iterable[_T]) -> None: ...
     def __next__(self) -> _T: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     @classmethod
     # We use type[Any] and not type[_S] to not lose the type inference from __iterable
     def from_iterable(cls: type[Any], __iterable: Iterable[Iterable[_S]]) -> chain[_S]: ...
@@ -72,25 +71,25 @@ class chain(Iterator[_T], Generic[_T]):
 
 class compress(Iterator[_T], Generic[_T]):
     def __init__(self, data: Iterable[_T], selectors: Iterable[Any]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class dropwhile(Iterator[_T], Generic[_T]):
     def __init__(self, __predicate: _Predicate[_T], __iterable: Iterable[_T]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class filterfalse(Iterator[_T], Generic[_T]):
     def __init__(self, __predicate: _Predicate[_T] | None, __iterable: Iterable[_T]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class groupby(Iterator[tuple[_T, Iterator[_S]]], Generic[_T, _S]):
     @overload
-    def __new__(cls, iterable: Iterable[_T1], key: None = ...) -> groupby[_T1, _T1]: ...
+    def __new__(cls, iterable: Iterable[_T1], key: None = None) -> groupby[_T1, _T1]: ...
     @overload
     def __new__(cls, iterable: Iterable[_T1], key: Callable[[_T1], _T2]) -> groupby[_T2, _T1]: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[_T, Iterator[_S]]: ...
 
 class islice(Iterator[_T], Generic[_T]):
@@ -98,17 +97,17 @@ class islice(Iterator[_T], Generic[_T]):
     def __init__(self, __iterable: Iterable[_T], __stop: int | None) -> None: ...
     @overload
     def __init__(self, __iterable: Iterable[_T], __start: int | None, __stop: int | None, __step: int | None = ...) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class starmap(Iterator[_T], Generic[_T]):
     def __init__(self, __function: Callable[..., _T], __iterable: Iterable[Iterable[Any]]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 class takewhile(Iterator[_T], Generic[_T]):
     def __init__(self, __predicate: _Predicate[_T], __iterable: Iterable[_T]) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
 def tee(__iterable: Iterable[_T], __n: int = 2) -> tuple[Iterator[_T], ...]: ...
@@ -190,7 +189,7 @@ class zip_longest(Iterator[_T_co], Generic[_T_co]):
         *iterables: Iterable[_T],
         fillvalue: _T,
     ) -> zip_longest[tuple[_T, ...]]: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
 class product(Iterator[_T_co], Generic[_T_co]):
@@ -239,12 +238,12 @@ class product(Iterator[_T_co], Generic[_T_co]):
     def __new__(cls, *iterables: Iterable[_T1], repeat: int) -> product[tuple[_T1, ...]]: ...
     @overload
     def __new__(cls, *iterables: Iterable[Any], repeat: int = ...) -> product[tuple[Any, ...]]: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
 class permutations(Iterator[tuple[_T, ...]], Generic[_T]):
     def __init__(self, iterable: Iterable[_T], r: int | None = ...) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[_T, ...]: ...
 
 class combinations(Iterator[_T_co], Generic[_T_co]):
@@ -258,22 +257,22 @@ class combinations(Iterator[_T_co], Generic[_T_co]):
     def __new__(cls, iterable: Iterable[_T], r: Literal[5]) -> combinations[tuple[_T, _T, _T, _T, _T]]: ...
     @overload
     def __new__(cls, iterable: Iterable[_T], r: int) -> combinations[tuple[_T, ...]]: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> _T_co: ...
 
 class combinations_with_replacement(Iterator[tuple[_T, ...]], Generic[_T]):
     def __init__(self, iterable: Iterable[_T], r: int) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[_T, ...]: ...
 
 if sys.version_info >= (3, 10):
     class pairwise(Iterator[_T_co], Generic[_T_co]):
         def __new__(cls, __iterable: Iterable[_T]) -> pairwise[tuple[_T, _T]]: ...
-        def __iter__(self: Self) -> Self: ...
+        def __iter__(self) -> Self: ...
         def __next__(self) -> _T_co: ...
 
 if sys.version_info >= (3, 12):
     class batched(Iterator[_T_co], Generic[_T_co]):
-        def __new__(cls: type[Self], iterable: Iterable[_T_co], n: int) -> Self: ...
-        def __iter__(self: Self) -> Self: ...
+        def __new__(cls, iterable: Iterable[_T_co], n: int) -> Self: ...
+        def __iter__(self) -> Self: ...
         def __next__(self) -> tuple[_T_co, ...]: ...
diff --git a/mypy/typeshed/stdlib/keyword.pyi b/mypy/typeshed/stdlib/keyword.pyi
index c17c58012fd1..46c386048858 100644
--- a/mypy/typeshed/stdlib/keyword.pyi
+++ b/mypy/typeshed/stdlib/keyword.pyi
@@ -1,5 +1,6 @@
 import sys
 from collections.abc import Sequence
+from typing_extensions import Final
 
 if sys.version_info >= (3, 9):
     __all__ = ["iskeyword", "issoftkeyword", "kwlist", "softkwlist"]
@@ -8,8 +9,13 @@ else:
 
 def iskeyword(s: str) -> bool: ...
 
-kwlist: Sequence[str]
+# a list at runtime, but you're not meant to mutate it;
+# type it as a sequence
+kwlist: Final[Sequence[str]]
 
 if sys.version_info >= (3, 9):
     def issoftkeyword(s: str) -> bool: ...
-    softkwlist: Sequence[str]
+
+    # a list at runtime, but you're not meant to mutate it;
+    # type it as a sequence
+    softkwlist: Final[Sequence[str]]
diff --git a/mypy/typeshed/stdlib/lib2to3/pgen2/grammar.pyi b/mypy/typeshed/stdlib/lib2to3/pgen2/grammar.pyi
index aa0dd687659d..bef0a7922683 100644
--- a/mypy/typeshed/stdlib/lib2to3/pgen2/grammar.pyi
+++ b/mypy/typeshed/stdlib/lib2to3/pgen2/grammar.pyi
@@ -1,5 +1,5 @@
-from _typeshed import Self, StrPath
-from typing_extensions import TypeAlias
+from _typeshed import StrPath
+from typing_extensions import Self, TypeAlias
 
 _Label: TypeAlias = tuple[int, str | None]
 _DFA: TypeAlias = list[list[tuple[int, int]]]
@@ -17,7 +17,7 @@ class Grammar:
     start: int
     def dump(self, filename: StrPath) -> None: ...
     def load(self, filename: StrPath) -> None: ...
-    def copy(self: Self) -> Self: ...
+    def copy(self) -> Self: ...
     def report(self) -> None: ...
 
 opmap_raw: str
diff --git a/mypy/typeshed/stdlib/lib2to3/pytree.pyi b/mypy/typeshed/stdlib/lib2to3/pytree.pyi
index 5cf7db146e46..4f756c9768db 100644
--- a/mypy/typeshed/stdlib/lib2to3/pytree.pyi
+++ b/mypy/typeshed/stdlib/lib2to3/pytree.pyi
@@ -1,8 +1,7 @@
-from _typeshed import Self
 from collections.abc import Iterator
 from lib2to3.pgen2.grammar import Grammar
 from typing import Any
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 _NL: TypeAlias = Node | Leaf
 _Context: TypeAlias = tuple[str, int, int]
@@ -21,8 +20,8 @@ class Base:
     was_changed: bool
     was_checked: bool
     def __eq__(self, other: object) -> bool: ...
-    def _eq(self: Self, other: Self) -> bool: ...
-    def clone(self: Self) -> Self: ...
+    def _eq(self, other: Self) -> bool: ...
+    def clone(self) -> Self: ...
     def post_order(self) -> Iterator[_NL]: ...
     def pre_order(self) -> Iterator[_NL]: ...
     def replace(self, new: _NL | list[_NL]) -> None: ...
diff --git a/mypy/typeshed/stdlib/logging/__init__.pyi b/mypy/typeshed/stdlib/logging/__init__.pyi
index 231700653a32..c74afa45ded1 100644
--- a/mypy/typeshed/stdlib/logging/__init__.pyi
+++ b/mypy/typeshed/stdlib/logging/__init__.pyi
@@ -1,14 +1,14 @@
 import sys
 import threading
-from _typeshed import Self, StrPath, SupportsWrite
+from _typeshed import StrPath, SupportsWrite
 from collections.abc import Callable, Iterable, Mapping, MutableMapping, Sequence
 from io import TextIOWrapper
 from re import Pattern
 from string import Template
 from time import struct_time
 from types import FrameType, TracebackType
-from typing import Any, ClassVar, Generic, TextIO, TypeVar, Union, overload
-from typing_extensions import Literal, TypeAlias
+from typing import Any, ClassVar, Generic, TextIO, TypeVar, overload
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 11):
     from types import GenericAlias
@@ -61,7 +61,7 @@ __all__ = [
 if sys.version_info >= (3, 11):
     __all__ += ["getLevelNamesMapping"]
 
-_SysExcInfoType: TypeAlias = Union[tuple[type[BaseException], BaseException, TracebackType | None], tuple[None, None, None]]
+_SysExcInfoType: TypeAlias = tuple[type[BaseException], BaseException, TracebackType | None] | tuple[None, None, None]
 _ExcInfoType: TypeAlias = None | bool | _SysExcInfoType | BaseException
 _ArgsType: TypeAlias = tuple[object, ...] | Mapping[str, object]
 _FilterType: TypeAlias = Filter | Callable[[LogRecord], bool]
@@ -110,7 +110,7 @@ class Logger(Filterer):
     def setLevel(self, level: _Level) -> None: ...
     def isEnabledFor(self, level: int) -> bool: ...
     def getEffectiveLevel(self) -> int: ...
-    def getChild(self: Self, suffix: str) -> Self: ...  # see python/typing#980
+    def getChild(self, suffix: str) -> Self: ...  # see python/typing#980
     if sys.version_info >= (3, 8):
         def debug(
             self,
diff --git a/mypy/typeshed/stdlib/lzma.pyi b/mypy/typeshed/stdlib/lzma.pyi
index 2feb28a8e743..34bd6f3f8db1 100644
--- a/mypy/typeshed/stdlib/lzma.pyi
+++ b/mypy/typeshed/stdlib/lzma.pyi
@@ -1,8 +1,8 @@
 import io
-from _typeshed import ReadableBuffer, Self, StrOrBytesPath
+from _typeshed import ReadableBuffer, StrOrBytesPath
 from collections.abc import Mapping, Sequence
 from typing import IO, Any, TextIO, overload
-from typing_extensions import Literal, TypeAlias, final
+from typing_extensions import Literal, Self, TypeAlias, final
 
 __all__ = [
     "CHECK_NONE",
@@ -115,7 +115,7 @@ class LZMAFile(io.BufferedIOBase, IO[bytes]):
         preset: int | None = None,
         filters: _FilterChain | None = None,
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def peek(self, size: int = -1) -> bytes: ...
     def read(self, size: int | None = -1) -> bytes: ...
     def read1(self, size: int = -1) -> bytes: ...
diff --git a/mypy/typeshed/stdlib/mailbox.pyi b/mypy/typeshed/stdlib/mailbox.pyi
index 2fe9060e7b7c..8053fad88ea5 100644
--- a/mypy/typeshed/stdlib/mailbox.pyi
+++ b/mypy/typeshed/stdlib/mailbox.pyi
@@ -1,12 +1,12 @@
 import email.message
 import io
 import sys
-from _typeshed import Self, StrPath, SupportsNoArgReadline, SupportsRead
+from _typeshed import StrPath, SupportsNoArgReadline, SupportsRead
 from abc import ABCMeta, abstractmethod
 from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
 from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, Protocol, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -235,7 +235,7 @@ class _ProxyFile(Generic[AnyStr]):
     def tell(self) -> int: ...
     def seek(self, offset: int, whence: int = 0) -> None: ...
     def close(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, exc_type: type[BaseException] | None, exc: BaseException | None, tb: TracebackType | None) -> None: ...
     def readable(self) -> bool: ...
     def writable(self) -> bool: ...
diff --git a/mypy/typeshed/stdlib/marshal.pyi b/mypy/typeshed/stdlib/marshal.pyi
index da5d1a95a6f6..21f05c908479 100644
--- a/mypy/typeshed/stdlib/marshal.pyi
+++ b/mypy/typeshed/stdlib/marshal.pyi
@@ -1,31 +1,31 @@
 import builtins
 import types
 from _typeshed import ReadableBuffer, SupportsRead, SupportsWrite
-from typing import Any, Union
+from typing import Any
 from typing_extensions import TypeAlias
 
 version: int
 
-_Marshallable: TypeAlias = Union[
+_Marshallable: TypeAlias = (
     # handled in w_object() in marshal.c
-    None,
-    type[StopIteration],
-    builtins.ellipsis,
-    bool,
+    None
+    | type[StopIteration]
+    | builtins.ellipsis
+    | bool
     # handled in w_complex_object() in marshal.c
-    int,
-    float,
-    complex,
-    bytes,
-    str,
-    tuple[_Marshallable, ...],
-    list[Any],
-    dict[Any, Any],
-    set[Any],
-    frozenset[_Marshallable],
-    types.CodeType,
-    ReadableBuffer,
-]
+    | int
+    | float
+    | complex
+    | bytes
+    | str
+    | tuple[_Marshallable, ...]
+    | list[Any]
+    | dict[Any, Any]
+    | set[Any]
+    | frozenset[_Marshallable]
+    | types.CodeType
+    | ReadableBuffer
+)
 
 def dump(__value: _Marshallable, __file: SupportsWrite[bytes], __version: int = 4) -> None: ...
 def load(__file: SupportsRead[bytes]) -> Any: ...
diff --git a/mypy/typeshed/stdlib/mmap.pyi b/mypy/typeshed/stdlib/mmap.pyi
index 273cd0c6f4d4..c74ad3cda6db 100644
--- a/mypy/typeshed/stdlib/mmap.pyi
+++ b/mypy/typeshed/stdlib/mmap.pyi
@@ -1,7 +1,8 @@
 import sys
-from _typeshed import ReadableBuffer, Self, Unused
+from _typeshed import ReadableBuffer, Unused
 from collections.abc import Iterable, Iterator, Sized
 from typing import NoReturn, overload
+from typing_extensions import Self
 
 ACCESS_DEFAULT: int
 ACCESS_READ: int
@@ -73,7 +74,7 @@ class mmap(Iterable[int], Sized):
     # Doesn't actually exist, but the object is actually iterable because it has __getitem__ and __len__,
     # so we claim that there is also an __iter__ to help type checkers.
     def __iter__(self) -> Iterator[int]: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
 
 if sys.version_info >= (3, 8) and sys.platform != "win32":
diff --git a/mypy/typeshed/stdlib/multiprocessing/connection.pyi b/mypy/typeshed/stdlib/multiprocessing/connection.pyi
index 392e3168aaaa..d034373712e0 100644
--- a/mypy/typeshed/stdlib/multiprocessing/connection.pyi
+++ b/mypy/typeshed/stdlib/multiprocessing/connection.pyi
@@ -1,15 +1,15 @@
 import socket
 import sys
 import types
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from collections.abc import Iterable
-from typing import Any, Union
-from typing_extensions import SupportsIndex, TypeAlias
+from typing import Any
+from typing_extensions import Self, SupportsIndex, TypeAlias
 
 __all__ = ["Client", "Listener", "Pipe", "wait"]
 
 # https://docs.python.org/3/library/multiprocessing.html#address-formats
-_Address: TypeAlias = Union[str, tuple[str, int]]
+_Address: TypeAlias = str | tuple[str, int]
 
 class _ConnectionBase:
     def __init__(self, handle: SupportsIndex, readable: bool = True, writable: bool = True) -> None: ...
@@ -27,7 +27,7 @@ class _ConnectionBase:
     def recv_bytes_into(self, buf: Any, offset: int = 0) -> int: ...
     def recv(self) -> Any: ...
     def poll(self, timeout: float | None = 0.0) -> bool: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, exc_tb: types.TracebackType | None
     ) -> None: ...
@@ -47,7 +47,7 @@ class Listener:
     def address(self) -> _Address: ...
     @property
     def last_accepted(self) -> _Address | None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, exc_tb: types.TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/multiprocessing/dummy/connection.pyi b/mypy/typeshed/stdlib/multiprocessing/dummy/connection.pyi
index 1630472b3b06..fcd03a657319 100644
--- a/mypy/typeshed/stdlib/multiprocessing/dummy/connection.pyi
+++ b/mypy/typeshed/stdlib/multiprocessing/dummy/connection.pyi
@@ -1,14 +1,13 @@
-from _typeshed import Self
 from queue import Queue
 from types import TracebackType
-from typing import Any, Union
-from typing_extensions import TypeAlias
+from typing import Any
+from typing_extensions import Self, TypeAlias
 
 __all__ = ["Client", "Listener", "Pipe"]
 
 families: list[None]
 
-_Address: TypeAlias = Union[str, tuple[str, int]]
+_Address: TypeAlias = str | tuple[str, int]
 
 class Connection:
     _in: Any
@@ -17,7 +16,7 @@ class Connection:
     recv_bytes: Any
     send: Any
     send_bytes: Any
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
@@ -29,7 +28,7 @@ class Listener:
     _backlog_queue: Queue[Any] | None
     @property
     def address(self) -> Queue[Any] | None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/multiprocessing/managers.pyi b/mypy/typeshed/stdlib/multiprocessing/managers.pyi
index 1696714d187b..e035a1875650 100644
--- a/mypy/typeshed/stdlib/multiprocessing/managers.pyi
+++ b/mypy/typeshed/stdlib/multiprocessing/managers.pyi
@@ -1,11 +1,11 @@
 import queue
 import sys
 import threading
-from _typeshed import Self, SupportsKeysAndGetItem, SupportsRichComparison, SupportsRichComparisonT
+from _typeshed import SupportsKeysAndGetItem, SupportsRichComparison, SupportsRichComparisonT
 from collections.abc import Callable, Iterable, Iterator, Mapping, MutableMapping, MutableSequence, Sequence
 from types import TracebackType
 from typing import Any, AnyStr, ClassVar, Generic, TypeVar, overload
-from typing_extensions import SupportsIndex, TypeAlias
+from typing_extensions import Self, SupportsIndex, TypeAlias
 
 from .connection import Connection
 from .context import BaseContext
@@ -111,13 +111,13 @@ class BaseListProxy(BaseProxy, MutableSequence[_T]):
     # Use BaseListProxy[SupportsRichComparisonT] for the first overload rather than [SupportsRichComparison]
     # to work around invariance
     @overload
-    def sort(self: BaseListProxy[SupportsRichComparisonT], *, key: None = ..., reverse: bool = ...) -> None: ...
+    def sort(self: BaseListProxy[SupportsRichComparisonT], *, key: None = None, reverse: bool = ...) -> None: ...
     @overload
     def sort(self, *, key: Callable[[_T], SupportsRichComparison], reverse: bool = ...) -> None: ...
 
 class ListProxy(BaseListProxy[_T]):
-    def __iadd__(self: Self, __x: Iterable[_T]) -> Self: ...  # type: ignore[override]
-    def __imul__(self: Self, __n: SupportsIndex) -> Self: ...  # type: ignore[override]
+    def __iadd__(self, __x: Iterable[_T]) -> Self: ...  # type: ignore[override]
+    def __imul__(self, __n: SupportsIndex) -> Self: ...  # type: ignore[override]
 
 # Returned by BaseManager.get_server()
 class Server:
@@ -165,7 +165,7 @@ class BaseManager:
         method_to_typeid: Mapping[str, str] | None = None,
         create_method: bool = True,
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/multiprocessing/pool.pyi b/mypy/typeshed/stdlib/multiprocessing/pool.pyi
index 3e2d0c3cd51e..a19dd555e254 100644
--- a/mypy/typeshed/stdlib/multiprocessing/pool.pyi
+++ b/mypy/typeshed/stdlib/multiprocessing/pool.pyi
@@ -1,9 +1,8 @@
 import sys
-from _typeshed import Self
 from collections.abc import Callable, Iterable, Iterator, Mapping
 from types import TracebackType
 from typing import Any, Generic, TypeVar
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -62,7 +61,7 @@ class IMapIterator(Iterator[_T]):
     else:
         def __init__(self, cache: dict[int, IMapIterator[Any]]) -> None: ...
 
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def next(self, timeout: float | None = None) -> _T: ...
     def __next__(self, timeout: float | None = None) -> _T: ...
 
@@ -109,7 +108,7 @@ class Pool:
     def close(self) -> None: ...
     def terminate(self) -> None: ...
     def join(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/multiprocessing/shared_memory.pyi b/mypy/typeshed/stdlib/multiprocessing/shared_memory.pyi
index 841c947360e8..ae6e2a0ed19f 100644
--- a/mypy/typeshed/stdlib/multiprocessing/shared_memory.pyi
+++ b/mypy/typeshed/stdlib/multiprocessing/shared_memory.pyi
@@ -1,7 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Iterable
 from typing import Any, Generic, TypeVar, overload
+from typing_extensions import Self
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -29,7 +29,7 @@ class ShareableList(Generic[_SLT]):
     def __init__(self, sequence: Iterable[_SLT], *, name: str | None = None) -> None: ...
     def __getitem__(self, position: int) -> _SLT: ...
     def __setitem__(self, position: int, value: _SLT) -> None: ...
-    def __reduce__(self: Self) -> tuple[Self, tuple[_SLT, ...]]: ...
+    def __reduce__(self) -> tuple[Self, tuple[_SLT, ...]]: ...
     def __len__(self) -> int: ...
     @property
     def format(self) -> str: ...
diff --git a/mypy/typeshed/stdlib/nntplib.pyi b/mypy/typeshed/stdlib/nntplib.pyi
index 02e743ea9d1e..f948c1430c90 100644
--- a/mypy/typeshed/stdlib/nntplib.pyi
+++ b/mypy/typeshed/stdlib/nntplib.pyi
@@ -2,11 +2,11 @@ import datetime
 import socket
 import ssl
 import sys
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from builtins import list as _list  # conflicts with a method named "list"
 from collections.abc import Iterable
 from typing import IO, Any, NamedTuple
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = [
     "NNTP",
@@ -72,7 +72,7 @@ class NNTP:
         usenetrc: bool = False,
         timeout: float = ...,
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def getwelcome(self) -> str: ...
     def getcapabilities(self) -> dict[str, _list[str]]: ...
diff --git a/mypy/typeshed/stdlib/os/__init__.pyi b/mypy/typeshed/stdlib/os/__init__.pyi
index b1b9db9ae2a7..595b78789c6a 100644
--- a/mypy/typeshed/stdlib/os/__init__.pyi
+++ b/mypy/typeshed/stdlib/os/__init__.pyi
@@ -11,7 +11,6 @@ from _typeshed import (
     OpenBinaryModeWriting,
     OpenTextMode,
     ReadableBuffer,
-    Self,
     StrOrBytesPath,
     StrPath,
     SupportsLenAndGetItem,
@@ -26,7 +25,7 @@ from contextlib import AbstractContextManager
 from io import BufferedRandom, BufferedReader, BufferedWriter, FileIO, TextIOWrapper as _TextIOWrapper
 from subprocess import Popen
 from typing import IO, Any, AnyStr, BinaryIO, Generic, NoReturn, Protocol, TypeVar, overload, runtime_checkable
-from typing_extensions import Final, Literal, TypeAlias, final
+from typing_extensions import Final, Literal, Self, TypeAlias, final
 
 from . import path as _path
 
@@ -245,9 +244,9 @@ class _Environ(MutableMapping[AnyStr, AnyStr], Generic[AnyStr]):
         # overloading MutableMapping.update in stdlib/typing.pyi
         # The type: ignore is needed due to incompatible __or__/__ior__ signatures
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, other: Mapping[AnyStr, AnyStr]) -> Self: ...
+        def __ior__(self, other: Mapping[AnyStr, AnyStr]) -> Self: ...
         @overload
-        def __ior__(self: Self, other: Iterable[tuple[AnyStr, AnyStr]]) -> Self: ...
+        def __ior__(self, other: Iterable[tuple[AnyStr, AnyStr]]) -> Self: ...
 
 environ: _Environ[str]
 if sys.platform != "win32":
@@ -530,8 +529,8 @@ def fdopen(
     mode: OpenBinaryMode,
     buffering: Literal[0],
     encoding: None = None,
-    errors: None = ...,
-    newline: None = ...,
+    errors: None = None,
+    newline: None = None,
     closefd: bool = ...,
     opener: _Opener | None = ...,
 ) -> FileIO: ...
@@ -541,8 +540,8 @@ def fdopen(
     mode: OpenBinaryModeUpdating,
     buffering: Literal[-1, 1] = -1,
     encoding: None = None,
-    errors: None = ...,
-    newline: None = ...,
+    errors: None = None,
+    newline: None = None,
     closefd: bool = ...,
     opener: _Opener | None = ...,
 ) -> BufferedRandom: ...
@@ -552,8 +551,8 @@ def fdopen(
     mode: OpenBinaryModeWriting,
     buffering: Literal[-1, 1] = -1,
     encoding: None = None,
-    errors: None = ...,
-    newline: None = ...,
+    errors: None = None,
+    newline: None = None,
     closefd: bool = ...,
     opener: _Opener | None = ...,
 ) -> BufferedWriter: ...
@@ -563,8 +562,8 @@ def fdopen(
     mode: OpenBinaryModeReading,
     buffering: Literal[-1, 1] = -1,
     encoding: None = None,
-    errors: None = ...,
-    newline: None = ...,
+    errors: None = None,
+    newline: None = None,
     closefd: bool = ...,
     opener: _Opener | None = ...,
 ) -> BufferedReader: ...
@@ -574,8 +573,8 @@ def fdopen(
     mode: OpenBinaryMode,
     buffering: int = -1,
     encoding: None = None,
-    errors: None = ...,
-    newline: None = ...,
+    errors: None = None,
+    newline: None = None,
     closefd: bool = ...,
     opener: _Opener | None = ...,
 ) -> BinaryIO: ...
@@ -958,7 +957,7 @@ if sys.platform != "win32":
     class sched_param(structseq[int], tuple[int]):
         if sys.version_info >= (3, 10):
             __match_args__: Final = ("sched_priority",)
-        def __new__(cls: type[Self], sched_priority: int) -> Self: ...
+        def __new__(cls, sched_priority: int) -> Self: ...
         @property
         def sched_priority(self) -> int: ...
 
@@ -1001,7 +1000,7 @@ if sys.version_info >= (3, 8):
             path: str | None
             def __init__(self, path: str | None, cookie: _T, remove_dll_directory: Callable[[_T], object]) -> None: ...
             def close(self) -> None: ...
-            def __enter__(self: Self) -> Self: ...
+            def __enter__(self) -> Self: ...
             def __exit__(self, *args: Unused) -> None: ...
 
         def add_dll_directory(path: str) -> _AddedDllDirectory: ...
diff --git a/mypy/typeshed/stdlib/pathlib.pyi b/mypy/typeshed/stdlib/pathlib.pyi
index 5220a142fb13..114678ed574d 100644
--- a/mypy/typeshed/stdlib/pathlib.pyi
+++ b/mypy/typeshed/stdlib/pathlib.pyi
@@ -6,7 +6,6 @@ from _typeshed import (
     OpenBinaryModeWriting,
     OpenTextMode,
     ReadableBuffer,
-    Self,
     StrOrBytesPath,
     StrPath,
 )
@@ -15,7 +14,7 @@ from io import BufferedRandom, BufferedReader, BufferedWriter, FileIO, TextIOWra
 from os import PathLike, stat_result
 from types import TracebackType
 from typing import IO, Any, BinaryIO, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -39,15 +38,15 @@ class PurePath(PathLike[str]):
     def suffixes(self) -> list[str]: ...
     @property
     def stem(self) -> str: ...
-    def __new__(cls: type[Self], *args: StrPath) -> Self: ...
+    def __new__(cls, *args: StrPath) -> Self: ...
     def __eq__(self, other: object) -> bool: ...
     def __fspath__(self) -> str: ...
     def __lt__(self, other: PurePath) -> bool: ...
     def __le__(self, other: PurePath) -> bool: ...
     def __gt__(self, other: PurePath) -> bool: ...
     def __ge__(self, other: PurePath) -> bool: ...
-    def __truediv__(self: Self, key: StrPath) -> Self: ...
-    def __rtruediv__(self: Self, key: StrPath) -> Self: ...
+    def __truediv__(self, key: StrPath) -> Self: ...
+    def __rtruediv__(self, key: StrPath) -> Self: ...
     def __bytes__(self) -> bytes: ...
     def as_posix(self) -> str: ...
     def as_uri(self) -> str: ...
@@ -57,17 +56,17 @@ class PurePath(PathLike[str]):
         def is_relative_to(self, *other: StrPath) -> bool: ...
 
     def match(self, path_pattern: str) -> bool: ...
-    def relative_to(self: Self, *other: StrPath) -> Self: ...
-    def with_name(self: Self, name: str) -> Self: ...
+    def relative_to(self, *other: StrPath) -> Self: ...
+    def with_name(self, name: str) -> Self: ...
     if sys.version_info >= (3, 9):
-        def with_stem(self: Self, stem: str) -> Self: ...
+        def with_stem(self, stem: str) -> Self: ...
 
-    def with_suffix(self: Self, suffix: str) -> Self: ...
-    def joinpath(self: Self, *other: StrPath) -> Self: ...
+    def with_suffix(self, suffix: str) -> Self: ...
+    def joinpath(self, *other: StrPath) -> Self: ...
     @property
-    def parents(self: Self) -> Sequence[Self]: ...
+    def parents(self) -> Sequence[Self]: ...
     @property
-    def parent(self: Self) -> Self: ...
+    def parent(self) -> Self: ...
     if sys.version_info >= (3, 9) and sys.version_info < (3, 11):
         def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
@@ -75,11 +74,11 @@ class PurePosixPath(PurePath): ...
 class PureWindowsPath(PurePath): ...
 
 class Path(PurePath):
-    def __new__(cls: type[Self], *args: StrPath, **kwargs: Any) -> Self: ...
-    def __enter__(self: Self) -> Self: ...
+    def __new__(cls, *args: StrPath, **kwargs: Any) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
     @classmethod
-    def cwd(cls: type[Self]) -> Self: ...
+    def cwd(cls) -> Self: ...
     if sys.version_info >= (3, 10):
         def stat(self, *, follow_symlinks: bool = True) -> stat_result: ...
         def chmod(self, mode: int, *, follow_symlinks: bool = True) -> None: ...
@@ -88,7 +87,7 @@ class Path(PurePath):
         def chmod(self, mode: int) -> None: ...
 
     def exists(self) -> bool: ...
-    def glob(self: Self, pattern: str) -> Generator[Self, None, None]: ...
+    def glob(self, pattern: str) -> Generator[Self, None, None]: ...
     def is_dir(self) -> bool: ...
     def is_file(self) -> bool: ...
     def is_symlink(self) -> bool: ...
@@ -96,7 +95,7 @@ class Path(PurePath):
     def is_fifo(self) -> bool: ...
     def is_block_device(self) -> bool: ...
     def is_char_device(self) -> bool: ...
-    def iterdir(self: Self) -> Generator[Self, None, None]: ...
+    def iterdir(self) -> Generator[Self, None, None]: ...
     def lchmod(self, mode: int) -> None: ...
     def lstat(self) -> stat_result: ...
     def mkdir(self, mode: int = 0o777, parents: bool = False, exist_ok: bool = False) -> None: ...
@@ -163,16 +162,16 @@ class Path(PurePath):
         def is_mount(self) -> bool: ...
 
     if sys.version_info >= (3, 9):
-        def readlink(self: Self) -> Self: ...
+        def readlink(self) -> Self: ...
     if sys.version_info >= (3, 8):
-        def rename(self: Self, target: str | PurePath) -> Self: ...
-        def replace(self: Self, target: str | PurePath) -> Self: ...
+        def rename(self, target: str | PurePath) -> Self: ...
+        def replace(self, target: str | PurePath) -> Self: ...
     else:
         def rename(self, target: str | PurePath) -> None: ...
         def replace(self, target: str | PurePath) -> None: ...
 
-    def resolve(self: Self, strict: bool = False) -> Self: ...
-    def rglob(self: Self, pattern: str) -> Generator[Self, None, None]: ...
+    def resolve(self, strict: bool = False) -> Self: ...
+    def rglob(self, pattern: str) -> Generator[Self, None, None]: ...
     def rmdir(self) -> None: ...
     def symlink_to(self, target: str | Path, target_is_directory: bool = False) -> None: ...
     if sys.version_info >= (3, 10):
@@ -185,9 +184,9 @@ class Path(PurePath):
         def unlink(self) -> None: ...
 
     @classmethod
-    def home(cls: type[Self]) -> Self: ...
-    def absolute(self: Self) -> Self: ...
-    def expanduser(self: Self) -> Self: ...
+    def home(cls) -> Self: ...
+    def absolute(self) -> Self: ...
+    def expanduser(self) -> Self: ...
     def read_bytes(self) -> bytes: ...
     def read_text(self, encoding: str | None = None, errors: str | None = None) -> str: ...
     def samefile(self, other_path: StrPath) -> bool: ...
@@ -202,7 +201,7 @@ class Path(PurePath):
         def link_to(self, target: StrOrBytesPath) -> None: ...
     if sys.version_info >= (3, 12):
         def walk(
-            self: Self, top_down: bool = ..., on_error: Callable[[OSError], object] | None = ..., follow_symlinks: bool = ...
+            self, top_down: bool = ..., on_error: Callable[[OSError], object] | None = ..., follow_symlinks: bool = ...
         ) -> Iterator[tuple[Self, list[str], list[str]]]: ...
 
 class PosixPath(Path, PurePosixPath): ...
diff --git a/mypy/typeshed/stdlib/pdb.pyi b/mypy/typeshed/stdlib/pdb.pyi
index a2b6636d8665..e2871bb54fa0 100644
--- a/mypy/typeshed/stdlib/pdb.pyi
+++ b/mypy/typeshed/stdlib/pdb.pyi
@@ -1,13 +1,12 @@
 import signal
 import sys
-from _typeshed import Self
 from bdb import Bdb
 from cmd import Cmd
 from collections.abc import Callable, Iterable, Mapping, Sequence
 from inspect import _SourceObjectType
 from types import CodeType, FrameType, TracebackType
 from typing import IO, Any, ClassVar, TypeVar
-from typing_extensions import ParamSpec
+from typing_extensions import ParamSpec, Self
 
 __all__ = ["run", "pm", "Pdb", "runeval", "runctx", "runcall", "set_trace", "post_mortem", "help"]
 
@@ -173,4 +172,4 @@ def getsourcelines(obj: _SourceObjectType) -> tuple[list[str], int]: ...
 def lasti2lineno(code: CodeType, lasti: int) -> int: ...
 
 class _rstr(str):
-    def __repr__(self: Self) -> Self: ...
+    def __repr__(self) -> Self: ...
diff --git a/mypy/typeshed/stdlib/pickle.pyi b/mypy/typeshed/stdlib/pickle.pyi
index dc098cae97b7..57c4cb03e484 100644
--- a/mypy/typeshed/stdlib/pickle.pyi
+++ b/mypy/typeshed/stdlib/pickle.pyi
@@ -1,7 +1,7 @@
 import sys
 from _typeshed import ReadableBuffer, SupportsWrite
 from collections.abc import Callable, Iterable, Iterator, Mapping
-from typing import Any, ClassVar, Protocol, SupportsBytes, Union
+from typing import Any, ClassVar, Protocol, SupportsBytes
 from typing_extensions import SupportsIndex, TypeAlias, final
 
 __all__ = [
@@ -142,13 +142,13 @@ class PickleError(Exception): ...
 class PicklingError(PickleError): ...
 class UnpicklingError(PickleError): ...
 
-_ReducedType: TypeAlias = Union[
-    str,
-    tuple[Callable[..., Any], tuple[Any, ...]],
-    tuple[Callable[..., Any], tuple[Any, ...], Any],
-    tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None],
-    tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None, Iterator[Any] | None],
-]
+_ReducedType: TypeAlias = (
+    str
+    | tuple[Callable[..., Any], tuple[Any, ...]]
+    | tuple[Callable[..., Any], tuple[Any, ...], Any]
+    | tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None]
+    | tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None, Iterator[Any] | None]
+)
 
 class Pickler:
     fast: bool
diff --git a/mypy/typeshed/stdlib/plistlib.pyi b/mypy/typeshed/stdlib/plistlib.pyi
index 54ce3dc61abc..5b76c935f76e 100644
--- a/mypy/typeshed/stdlib/plistlib.pyi
+++ b/mypy/typeshed/stdlib/plistlib.pyi
@@ -1,9 +1,10 @@
 import sys
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from collections.abc import Mapping, MutableMapping
 from datetime import datetime
 from enum import Enum
 from typing import IO, Any
+from typing_extensions import Self
 
 if sys.version_info >= (3, 9):
     __all__ = ["InvalidFileException", "FMT_XML", "FMT_BINARY", "load", "dump", "loads", "dumps", "UID"]
@@ -100,7 +101,7 @@ if sys.version_info >= (3, 8):
         data: int
         def __init__(self, data: int) -> None: ...
         def __index__(self) -> int: ...
-        def __reduce__(self: Self) -> tuple[type[Self], tuple[int]]: ...
+        def __reduce__(self) -> tuple[type[Self], tuple[int]]: ...
         def __eq__(self, other: object) -> bool: ...
 
 class InvalidFileException(ValueError):
diff --git a/mypy/typeshed/stdlib/profile.pyi b/mypy/typeshed/stdlib/profile.pyi
index 8d6e9b220587..6ae375004158 100644
--- a/mypy/typeshed/stdlib/profile.pyi
+++ b/mypy/typeshed/stdlib/profile.pyi
@@ -1,7 +1,7 @@
-from _typeshed import Self, StrOrBytesPath
+from _typeshed import StrOrBytesPath
 from collections.abc import Callable
 from typing import Any, TypeVar
-from typing_extensions import ParamSpec, TypeAlias
+from typing_extensions import ParamSpec, Self, TypeAlias
 
 __all__ = ["run", "runctx", "Profile"]
 
@@ -25,7 +25,7 @@ class Profile:
     def dump_stats(self, file: StrOrBytesPath) -> None: ...
     def create_stats(self) -> None: ...
     def snapshot_stats(self) -> None: ...
-    def run(self: Self, cmd: str) -> Self: ...
-    def runctx(self: Self, cmd: str, globals: dict[str, Any], locals: dict[str, Any]) -> Self: ...
+    def run(self, cmd: str) -> Self: ...
+    def runctx(self, cmd: str, globals: dict[str, Any], locals: dict[str, Any]) -> Self: ...
     def runcall(self, __func: Callable[_P, _T], *args: _P.args, **kw: _P.kwargs) -> _T: ...
     def calibrate(self, m: int, verbose: int = 0) -> float: ...
diff --git a/mypy/typeshed/stdlib/pstats.pyi b/mypy/typeshed/stdlib/pstats.pyi
index f4f331934565..5d25d1bb3641 100644
--- a/mypy/typeshed/stdlib/pstats.pyi
+++ b/mypy/typeshed/stdlib/pstats.pyi
@@ -1,11 +1,11 @@
 import sys
-from _typeshed import Self, StrOrBytesPath
+from _typeshed import StrOrBytesPath
 from collections.abc import Iterable
 from cProfile import Profile as _cProfile
 from enum import Enum
 from profile import Profile
 from typing import IO, Any, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     __all__ = ["Stats", "SortKey", "FunctionProfile", "StatsProfile"]
@@ -47,7 +47,7 @@ _SortArgDict: TypeAlias = dict[str, tuple[tuple[tuple[int, int], ...], str]]
 class Stats:
     sort_arg_dict_default: _SortArgDict
     def __init__(
-        self: Self,
+        self,
         __arg: None | str | Profile | _cProfile = ...,
         *args: None | str | Profile | _cProfile | Self,
         stream: IO[Any] | None = None,
@@ -55,24 +55,24 @@ class Stats:
     def init(self, arg: None | str | Profile | _cProfile) -> None: ...
     def load_stats(self, arg: None | str | Profile | _cProfile) -> None: ...
     def get_top_level_stats(self) -> None: ...
-    def add(self: Self, *arg_list: None | str | Profile | _cProfile | Self) -> Self: ...
+    def add(self, *arg_list: None | str | Profile | _cProfile | Self) -> Self: ...
     def dump_stats(self, filename: StrOrBytesPath) -> None: ...
     def get_sort_arg_defs(self) -> _SortArgDict: ...
     @overload
-    def sort_stats(self: Self, field: Literal[-1, 0, 1, 2]) -> Self: ...
+    def sort_stats(self, field: Literal[-1, 0, 1, 2]) -> Self: ...
     @overload
-    def sort_stats(self: Self, *field: str) -> Self: ...
-    def reverse_order(self: Self) -> Self: ...
-    def strip_dirs(self: Self) -> Self: ...
+    def sort_stats(self, *field: str) -> Self: ...
+    def reverse_order(self) -> Self: ...
+    def strip_dirs(self) -> Self: ...
     def calc_callees(self) -> None: ...
     def eval_print_amount(self, sel: _Selector, list: list[str], msg: str) -> tuple[list[str], str]: ...
     if sys.version_info >= (3, 9):
         def get_stats_profile(self) -> StatsProfile: ...
 
     def get_print_list(self, sel_list: Iterable[_Selector]) -> tuple[int, list[str]]: ...
-    def print_stats(self: Self, *amount: _Selector) -> Self: ...
-    def print_callees(self: Self, *amount: _Selector) -> Self: ...
-    def print_callers(self: Self, *amount: _Selector) -> Self: ...
+    def print_stats(self, *amount: _Selector) -> Self: ...
+    def print_callees(self, *amount: _Selector) -> Self: ...
+    def print_callers(self, *amount: _Selector) -> Self: ...
     def print_call_heading(self, name_size: int, column_title: str) -> None: ...
     def print_call_line(self, name_size: int, source: str, call_dict: dict[str, Any], arrow: str = "->") -> None: ...
     def print_title(self) -> None: ...
diff --git a/mypy/typeshed/stdlib/pydoc.pyi b/mypy/typeshed/stdlib/pydoc.pyi
index 9bcd8659fc8c..c6893d50c66a 100644
--- a/mypy/typeshed/stdlib/pydoc.pyi
+++ b/mypy/typeshed/stdlib/pydoc.pyi
@@ -6,16 +6,16 @@ from collections.abc import Callable, Container, Mapping, MutableMapping
 from reprlib import Repr
 from types import MethodType, ModuleType, TracebackType
 from typing import IO, Any, AnyStr, NoReturn, TypeVar
-from typing_extensions import TypeGuard
+from typing_extensions import Final, TypeGuard
 
 __all__ = ["help"]
 
 _T = TypeVar("_T")
 
-__author__: str
-__date__: str
-__version__: str
-__credits__: str
+__author__: Final[str]
+__date__: Final[str]
+__version__: Final[str]
+__credits__: Final[str]
 
 def pathdirs() -> list[str]: ...
 def getdoc(object: object) -> str: ...
diff --git a/mypy/typeshed/stdlib/quopri.pyi b/mypy/typeshed/stdlib/quopri.pyi
index 336f733f64c0..b652e139bd0e 100644
--- a/mypy/typeshed/stdlib/quopri.pyi
+++ b/mypy/typeshed/stdlib/quopri.pyi
@@ -5,7 +5,7 @@ __all__ = ["encode", "decode", "encodestring", "decodestring"]
 
 class _Input(SupportsRead[bytes], SupportsNoArgReadline[bytes], Protocol): ...
 
-def encode(input: _Input, output: SupportsWrite[bytes], quotetabs: int, header: int = False) -> None: ...
-def encodestring(s: ReadableBuffer, quotetabs: int = False, header: int = False) -> bytes: ...
-def decode(input: _Input, output: SupportsWrite[bytes], header: int = False) -> None: ...
-def decodestring(s: str | ReadableBuffer, header: int = False) -> bytes: ...
+def encode(input: _Input, output: SupportsWrite[bytes], quotetabs: int, header: bool = False) -> None: ...
+def encodestring(s: ReadableBuffer, quotetabs: bool = False, header: bool = False) -> bytes: ...
+def decode(input: _Input, output: SupportsWrite[bytes], header: bool = False) -> None: ...
+def decodestring(s: str | ReadableBuffer, header: bool = False) -> bytes: ...
diff --git a/mypy/typeshed/stdlib/re.pyi b/mypy/typeshed/stdlib/re.pyi
index f45ac7383e5d..4e53141ade84 100644
--- a/mypy/typeshed/stdlib/re.pyi
+++ b/mypy/typeshed/stdlib/re.pyi
@@ -72,7 +72,7 @@ class Match(Generic[AnyStr]):
     def expand(self, template: AnyStr) -> AnyStr: ...
     # group() returns "AnyStr" or "AnyStr | None", depending on the pattern.
     @overload
-    def group(self, __group: Literal[0] = ...) -> AnyStr: ...
+    def group(self, __group: Literal[0] = 0) -> AnyStr: ...
     @overload
     def group(self, __group: str | int) -> AnyStr | Any: ...
     @overload
diff --git a/mypy/typeshed/stdlib/runpy.pyi b/mypy/typeshed/stdlib/runpy.pyi
index 7efc194c8c66..d4406ea4ac41 100644
--- a/mypy/typeshed/stdlib/runpy.pyi
+++ b/mypy/typeshed/stdlib/runpy.pyi
@@ -1,6 +1,7 @@
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from types import ModuleType
 from typing import Any
+from typing_extensions import Self
 
 __all__ = ["run_module", "run_path"]
 
@@ -8,7 +9,7 @@ class _TempModule:
     mod_name: str
     module: ModuleType
     def __init__(self, mod_name: str) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
 
 class _ModifiedArgv0:
diff --git a/mypy/typeshed/stdlib/select.pyi b/mypy/typeshed/stdlib/select.pyi
index d02651320cf6..412fd71ee38d 100644
--- a/mypy/typeshed/stdlib/select.pyi
+++ b/mypy/typeshed/stdlib/select.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import FileDescriptorLike, Self
+from _typeshed import FileDescriptorLike
 from collections.abc import Iterable
 from types import TracebackType
 from typing import Any
-from typing_extensions import final
+from typing_extensions import Self, final
 
 if sys.platform != "win32":
     PIPE_BUF: int
@@ -106,7 +106,7 @@ if sys.platform == "linux":
     @final
     class epoll:
         def __init__(self, sizehint: int = ..., flags: int = ...) -> None: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(
             self,
             __exc_type: type[BaseException] | None = None,
diff --git a/mypy/typeshed/stdlib/selectors.pyi b/mypy/typeshed/stdlib/selectors.pyi
index e15780fadee1..90a923f09355 100644
--- a/mypy/typeshed/stdlib/selectors.pyi
+++ b/mypy/typeshed/stdlib/selectors.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import FileDescriptor, FileDescriptorLike, Self, Unused
+from _typeshed import FileDescriptor, FileDescriptorLike, Unused
 from abc import ABCMeta, abstractmethod
 from collections.abc import Mapping
 from typing import Any, NamedTuple
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 _EventMask: TypeAlias = int
 
@@ -28,7 +28,7 @@ class BaseSelector(metaclass=ABCMeta):
     def get_key(self, fileobj: FileDescriptorLike) -> SelectorKey: ...
     @abstractmethod
     def get_map(self) -> Mapping[FileDescriptorLike, SelectorKey]: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
 
 class SelectSelector(BaseSelector):
diff --git a/mypy/typeshed/stdlib/shelve.pyi b/mypy/typeshed/stdlib/shelve.pyi
index d55e08bffa16..82d0b03f4049 100644
--- a/mypy/typeshed/stdlib/shelve.pyi
+++ b/mypy/typeshed/stdlib/shelve.pyi
@@ -1,8 +1,8 @@
-from _typeshed import Self
 from collections.abc import Iterator, MutableMapping
 from dbm import _TFlags
 from types import TracebackType
 from typing import Any, TypeVar, overload
+from typing_extensions import Self
 
 __all__ = ["Shelf", "BsdDbShelf", "DbfilenameShelf", "open"]
 
@@ -23,7 +23,7 @@ class Shelf(MutableMapping[str, _VT]):
     def __setitem__(self, key: str, value: _VT) -> None: ...
     def __delitem__(self, key: str) -> None: ...
     def __contains__(self, key: str) -> bool: ...  # type: ignore[override]
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/shlex.pyi b/mypy/typeshed/stdlib/shlex.pyi
index 9a578d186be8..fa04932db676 100644
--- a/mypy/typeshed/stdlib/shlex.pyi
+++ b/mypy/typeshed/stdlib/shlex.pyi
@@ -1,7 +1,7 @@
 import sys
-from _typeshed import Self
 from collections.abc import Iterable
 from typing import TextIO
+from typing_extensions import Self
 
 if sys.version_info >= (3, 8):
     __all__ = ["shlex", "split", "quote", "join"]
@@ -46,5 +46,5 @@ class shlex(Iterable[str]):
     def push_source(self, newstream: str | TextIO, newfile: str | None = None) -> None: ...
     def pop_source(self) -> None: ...
     def error_leader(self, infile: str | None = None, lineno: int | None = None) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> str: ...
diff --git a/mypy/typeshed/stdlib/signal.pyi b/mypy/typeshed/stdlib/signal.pyi
index e0d7364c6b4e..e411d47016b6 100644
--- a/mypy/typeshed/stdlib/signal.pyi
+++ b/mypy/typeshed/stdlib/signal.pyi
@@ -3,7 +3,7 @@ from _typeshed import structseq
 from collections.abc import Callable, Iterable
 from enum import IntEnum
 from types import FrameType
-from typing import Any, Union
+from typing import Any
 from typing_extensions import Final, Never, TypeAlias, final
 
 NSIG: int
@@ -62,7 +62,7 @@ SIG_DFL: Handlers
 SIG_IGN: Handlers
 
 _SIGNUM: TypeAlias = int | Signals
-_HANDLER: TypeAlias = Union[Callable[[int, FrameType | None], Any], int, Handlers, None]
+_HANDLER: TypeAlias = Callable[[int, FrameType | None], Any] | int | Handlers | None
 
 def default_int_handler(__signalnum: int, __frame: FrameType | None) -> Never: ...
 
@@ -113,7 +113,7 @@ else:
     SIGXCPU: Signals
     SIGXFSZ: Signals
 
-    class ItimerError(IOError): ...
+    class ItimerError(OSError): ...
     ITIMER_PROF: int
     ITIMER_REAL: int
     ITIMER_VIRTUAL: int
@@ -178,4 +178,4 @@ def set_wakeup_fd(fd: int, *, warn_on_full_buffer: bool = ...) -> int: ...
 
 if sys.version_info >= (3, 9):
     if sys.platform == "linux":
-        def pidfd_send_signal(__pidfd: int, __sig: int, __siginfo: None = ..., __flags: int = ...) -> None: ...
+        def pidfd_send_signal(__pidfd: int, __sig: int, __siginfo: None = None, __flags: int = ...) -> None: ...
diff --git a/mypy/typeshed/stdlib/smtplib.pyi b/mypy/typeshed/stdlib/smtplib.pyi
index d0d674242bf8..0d7595fc1d6d 100644
--- a/mypy/typeshed/stdlib/smtplib.pyi
+++ b/mypy/typeshed/stdlib/smtplib.pyi
@@ -1,6 +1,6 @@
 import sys
 from _socket import _Address as _SourceAddress
-from _typeshed import ReadableBuffer, Self, _BufferWithLen
+from _typeshed import ReadableBuffer, _BufferWithLen
 from collections.abc import Sequence
 from email.message import Message as _Message
 from re import Pattern
@@ -8,7 +8,7 @@ from socket import socket
 from ssl import SSLContext
 from types import TracebackType
 from typing import Any, Protocol, overload
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "SMTPException",
@@ -68,7 +68,7 @@ def quotedata(data: str) -> str: ...
 
 class _AuthObject(Protocol):
     @overload
-    def __call__(self, challenge: None = ...) -> str | None: ...
+    def __call__(self, challenge: None = None) -> str | None: ...
     @overload
     def __call__(self, challenge: bytes) -> str: ...
 
@@ -95,7 +95,7 @@ class SMTP:
         timeout: float = ...,
         source_address: _SourceAddress | None = None,
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/socket.pyi b/mypy/typeshed/stdlib/socket.pyi
index 4481f398867c..dbc1d46ec1d4 100644
--- a/mypy/typeshed/stdlib/socket.pyi
+++ b/mypy/typeshed/stdlib/socket.pyi
@@ -112,12 +112,12 @@ from _socket import (
     setdefaulttimeout as setdefaulttimeout,
     timeout as timeout,
 )
-from _typeshed import ReadableBuffer, Self, Unused, WriteableBuffer
+from _typeshed import ReadableBuffer, Unused, WriteableBuffer
 from collections.abc import Iterable
 from enum import IntEnum, IntFlag
 from io import BufferedReader, BufferedRWPair, BufferedWriter, IOBase, RawIOBase, TextIOWrapper
 from typing import Any, Protocol, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 if sys.platform != "darwin" or sys.version_info >= (3, 9):
     from _socket import (
@@ -657,9 +657,9 @@ class socket(_socket.socket):
     def __init__(
         self, family: AddressFamily | int = -1, type: SocketKind | int = -1, proto: int = -1, fileno: int | None = None
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
-    def dup(self: Self) -> Self: ...  # noqa: F811
+    def dup(self) -> Self: ...  # noqa: F811
     def accept(self) -> tuple[socket, _RetAddress]: ...
     # Note that the makefile's documented windows-specific behavior is not represented
     # mode strings with duplicates are intentionally excluded
diff --git a/mypy/typeshed/stdlib/socketserver.pyi b/mypy/typeshed/stdlib/socketserver.pyi
index b35f1553fb44..3f0bb0eea0ce 100644
--- a/mypy/typeshed/stdlib/socketserver.pyi
+++ b/mypy/typeshed/stdlib/socketserver.pyi
@@ -1,11 +1,11 @@
 import sys
 import types
 from _socket import _Address, _RetAddress
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from collections.abc import Callable
 from socket import socket as _socket
-from typing import Any, BinaryIO, ClassVar, Union
-from typing_extensions import TypeAlias
+from typing import Any, BinaryIO, ClassVar
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "BaseServer",
@@ -29,7 +29,7 @@ if sys.platform != "win32":
         "UnixStreamServer",
     ]
 
-_RequestType: TypeAlias = Union[_socket, tuple[bytes, _socket]]
+_RequestType: TypeAlias = _socket | tuple[bytes, _socket]
 _AfUnixAddress: TypeAlias = str | ReadableBuffer  # adddress acceptable for an AF_UNIX socket
 _AfInetAddress: TypeAlias = tuple[str | bytes | bytearray, int]  # address acceptable for an AF_INET socket
 
@@ -43,13 +43,13 @@ class BaseServer:
     socket_type: int
     timeout: float | None
     def __init__(
-        self: Self, server_address: _Address, RequestHandlerClass: Callable[[Any, _RetAddress, Self], BaseRequestHandler]
+        self, server_address: _Address, RequestHandlerClass: Callable[[Any, _RetAddress, Self], BaseRequestHandler]
     ) -> None: ...
     # It is not actually a `@property`, but we need a `Self` type:
     @property
-    def RequestHandlerClass(self: Self) -> Callable[[Any, _RetAddress, Self], BaseRequestHandler]: ...
+    def RequestHandlerClass(self) -> Callable[[Any, _RetAddress, Self], BaseRequestHandler]: ...
     @RequestHandlerClass.setter
-    def RequestHandlerClass(self: Self, val: Callable[[Any, _RetAddress, Self], BaseRequestHandler]) -> None: ...
+    def RequestHandlerClass(self, val: Callable[[Any, _RetAddress, Self], BaseRequestHandler]) -> None: ...
     def fileno(self) -> int: ...
     def handle_request(self) -> None: ...
     def serve_forever(self, poll_interval: float = 0.5) -> None: ...
@@ -63,7 +63,7 @@ class BaseServer:
     def server_activate(self) -> None: ...
     def server_bind(self) -> None: ...
     def verify_request(self, request: _RequestType, client_address: _RetAddress) -> bool: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: types.TracebackType | None
     ) -> None: ...
@@ -76,7 +76,7 @@ class TCPServer(BaseServer):
         allow_reuse_port: bool
     server_address: _AfInetAddress  # type: ignore[assignment]
     def __init__(
-        self: Self,
+        self,
         server_address: _AfInetAddress,
         RequestHandlerClass: Callable[[Any, _RetAddress, Self], BaseRequestHandler],
         bind_and_activate: bool = True,
@@ -91,7 +91,7 @@ if sys.platform != "win32":
     class UnixStreamServer(BaseServer):
         server_address: _AfUnixAddress  # type: ignore[assignment]
         def __init__(
-            self: Self,
+            self,
             server_address: _AfUnixAddress,
             RequestHandlerClass: Callable[[Any, _RetAddress, Self], BaseRequestHandler],
             bind_and_activate: bool = True,
@@ -100,7 +100,7 @@ if sys.platform != "win32":
     class UnixDatagramServer(BaseServer):
         server_address: _AfUnixAddress  # type: ignore[assignment]
         def __init__(
-            self: Self,
+            self,
             server_address: _AfUnixAddress,
             RequestHandlerClass: Callable[[Any, _RetAddress, Self], BaseRequestHandler],
             bind_and_activate: bool = True,
diff --git a/mypy/typeshed/stdlib/sqlite3/dbapi2.pyi b/mypy/typeshed/stdlib/sqlite3/dbapi2.pyi
index 01274d6e2a60..26188445547e 100644
--- a/mypy/typeshed/stdlib/sqlite3/dbapi2.pyi
+++ b/mypy/typeshed/stdlib/sqlite3/dbapi2.pyi
@@ -1,11 +1,11 @@
 import sqlite3
 import sys
-from _typeshed import Incomplete, ReadableBuffer, Self, StrOrBytesPath, SupportsLenAndGetItem, Unused
+from _typeshed import Incomplete, ReadableBuffer, StrOrBytesPath, SupportsLenAndGetItem, Unused
 from collections.abc import Callable, Generator, Iterable, Iterator, Mapping
 from datetime import date, datetime, time
 from types import TracebackType
 from typing import Any, Protocol, TypeVar, overload
-from typing_extensions import Literal, SupportsIndex, TypeAlias, final
+from typing_extensions import Literal, Self, SupportsIndex, TypeAlias, final
 
 _T = TypeVar("_T")
 _CursorT = TypeVar("_CursorT", bound=Cursor)
@@ -324,7 +324,7 @@ class Connection:
         def create_function(self, name: str, num_params: int, func: Callable[..., _SqliteData] | None) -> None: ...
 
     @overload
-    def cursor(self, cursorClass: None = ...) -> Cursor: ...
+    def cursor(self, cursorClass: None = None) -> Cursor: ...
     @overload
     def cursor(self, cursorClass: Callable[[], _CursorT]) -> _CursorT: ...
     def execute(self, sql: str, parameters: _Parameters = ...) -> Cursor: ...
@@ -358,7 +358,7 @@ class Connection:
         def deserialize(self, __data: ReadableBuffer, *, name: str = "main") -> None: ...
 
     def __call__(self, __sql: str) -> _Statement: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, __type: type[BaseException] | None, __value: BaseException | None, __traceback: TracebackType | None
     ) -> Literal[False]: ...
@@ -377,8 +377,8 @@ class Cursor(Iterator[Any]):
     def rowcount(self) -> int: ...
     def __init__(self, __cursor: Connection) -> None: ...
     def close(self) -> None: ...
-    def execute(self: Self, __sql: str, __parameters: _Parameters = ...) -> Self: ...
-    def executemany(self: Self, __sql: str, __seq_of_parameters: Iterable[_Parameters]) -> Self: ...
+    def execute(self, __sql: str, __parameters: _Parameters = ...) -> Self: ...
+    def executemany(self, __sql: str, __seq_of_parameters: Iterable[_Parameters]) -> Self: ...
     def executescript(self, __sql_script: str) -> Cursor: ...
     def fetchall(self) -> list[Any]: ...
     def fetchmany(self, size: int | None = 1) -> list[Any]: ...
@@ -387,7 +387,7 @@ class Cursor(Iterator[Any]):
     def fetchone(self) -> Any: ...
     def setinputsizes(self, __sizes: Unused) -> None: ...  # does nothing
     def setoutputsize(self, __size: Unused, __column: Unused = None) -> None: ...  # does nothing
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> Any: ...
 
 class DataError(DatabaseError): ...
@@ -452,7 +452,7 @@ if sys.version_info >= (3, 11):
         # whence must be one of os.SEEK_SET, os.SEEK_CUR, os.SEEK_END
         def seek(self, __offset: int, __origin: int = 0) -> None: ...
         def __len__(self) -> int: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(self, __typ: object, __val: object, __tb: object) -> Literal[False]: ...
         def __getitem__(self, __item: SupportsIndex | slice) -> int: ...
         def __setitem__(self, __item: SupportsIndex | slice, __value: int) -> None: ...
diff --git a/mypy/typeshed/stdlib/sre_constants.pyi b/mypy/typeshed/stdlib/sre_constants.pyi
index fe25eaf9728e..d522372c438c 100644
--- a/mypy/typeshed/stdlib/sre_constants.pyi
+++ b/mypy/typeshed/stdlib/sre_constants.pyi
@@ -1,6 +1,6 @@
 import sys
-from _typeshed import Self
 from typing import Any
+from typing_extensions import Self
 
 MAXGROUPS: int
 
@@ -16,7 +16,7 @@ class error(Exception):
 
 class _NamedIntConstant(int):
     name: Any
-    def __new__(cls: type[Self], value: int, name: str) -> Self: ...
+    def __new__(cls, value: int, name: str) -> Self: ...
 
 MAXREPEAT: _NamedIntConstant
 OPCODES: list[_NamedIntConstant]
diff --git a/mypy/typeshed/stdlib/ssl.pyi b/mypy/typeshed/stdlib/ssl.pyi
index f8b97fb60eb7..bbf8a4c6d65a 100644
--- a/mypy/typeshed/stdlib/ssl.pyi
+++ b/mypy/typeshed/stdlib/ssl.pyi
@@ -1,17 +1,17 @@
 import enum
 import socket
 import sys
-from _typeshed import ReadableBuffer, Self, StrOrBytesPath, WriteableBuffer
+from _typeshed import ReadableBuffer, StrOrBytesPath, WriteableBuffer
 from collections.abc import Callable, Iterable
-from typing import Any, NamedTuple, Union, overload
-from typing_extensions import Literal, TypeAlias, TypedDict, final
+from typing import Any, NamedTuple, overload
+from typing_extensions import Literal, Self, TypeAlias, TypedDict, final
 
 _PCTRTT: TypeAlias = tuple[tuple[str, str], ...]
 _PCTRTTT: TypeAlias = tuple[_PCTRTT, ...]
 _PeerCertRetDictType: TypeAlias = dict[str, str | _PCTRTTT | _PCTRTT]
 _PeerCertRetType: TypeAlias = _PeerCertRetDictType | bytes | None
 _EnumRetType: TypeAlias = list[tuple[bytes, str, set[str] | bool]]
-_PasswordType: TypeAlias = Union[Callable[[], str | bytes | bytearray], str, bytes, bytearray]
+_PasswordType: TypeAlias = Callable[[], str | bytes | bytearray] | str | bytes | bytearray
 
 _SrvnmeCbType: TypeAlias = Callable[[SSLSocket | SSLObject, str | None, SSLSocket], int | None]
 
@@ -297,9 +297,9 @@ class _ASN1Object(NamedTuple):
     longname: str
     oid: str
     @classmethod
-    def fromnid(cls: type[Self], nid: int) -> Self: ...
+    def fromnid(cls, nid: int) -> Self: ...
     @classmethod
-    def fromname(cls: type[Self], name: str) -> Self: ...
+    def fromname(cls, name: str) -> Self: ...
 
 class Purpose(_ASN1Object, enum.Enum):
     SERVER_AUTH: _ASN1Object
@@ -383,9 +383,9 @@ class SSLContext:
     if sys.version_info >= (3, 10):
         # Using the default (None) for the `protocol` parameter is deprecated,
         # but there isn't a good way of marking that in the stub unless/until PEP 702 is accepted
-        def __new__(cls: type[Self], protocol: int | None = None, *args: Any, **kwargs: Any) -> Self: ...
+        def __new__(cls, protocol: int | None = None, *args: Any, **kwargs: Any) -> Self: ...
     else:
-        def __new__(cls: type[Self], protocol: int = ..., *args: Any, **kwargs: Any) -> Self: ...
+        def __new__(cls, protocol: int = ..., *args: Any, **kwargs: Any) -> Self: ...
 
     def cert_store_stats(self) -> dict[str, int]: ...
     def load_cert_chain(
diff --git a/mypy/typeshed/stdlib/statistics.pyi b/mypy/typeshed/stdlib/statistics.pyi
index 4ef950b9b4de..1358b1f90d7d 100644
--- a/mypy/typeshed/stdlib/statistics.pyi
+++ b/mypy/typeshed/stdlib/statistics.pyi
@@ -1,10 +1,10 @@
 import sys
-from _typeshed import Self, SupportsRichComparisonT
+from _typeshed import SupportsRichComparisonT
 from collections.abc import Hashable, Iterable, Sequence
 from decimal import Decimal
 from fractions import Fraction
 from typing import Any, NamedTuple, SupportsFloat, TypeVar
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = [
     "StatisticsError",
@@ -93,7 +93,7 @@ if sys.version_info >= (3, 8):
         @property
         def variance(self) -> float: ...
         @classmethod
-        def from_samples(cls: type[Self], data: Iterable[SupportsFloat]) -> Self: ...
+        def from_samples(cls, data: Iterable[SupportsFloat]) -> Self: ...
         def samples(self, n: int, *, seed: Any | None = None) -> list[float]: ...
         def pdf(self, x: float) -> float: ...
         def cdf(self, x: float) -> float: ...
diff --git a/mypy/typeshed/stdlib/subprocess.pyi b/mypy/typeshed/stdlib/subprocess.pyi
index 35a7b7e34f6b..3940fad7b915 100644
--- a/mypy/typeshed/stdlib/subprocess.pyi
+++ b/mypy/typeshed/stdlib/subprocess.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import ReadableBuffer, Self, StrOrBytesPath
+from _typeshed import ReadableBuffer, StrOrBytesPath
 from collections.abc import Callable, Collection, Iterable, Mapping, Sequence
 from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -257,8 +257,8 @@ if sys.version_info >= (3, 11):
         *,
         capture_output: bool = False,
         check: bool = False,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         input: ReadableBuffer | None = None,
         text: Literal[None, False] = ...,
         timeout: float | None = None,
@@ -461,8 +461,8 @@ elif sys.version_info >= (3, 10):
         *,
         capture_output: bool = False,
         check: bool = False,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         input: ReadableBuffer | None = None,
         text: Literal[None, False] = ...,
         timeout: float | None = None,
@@ -659,8 +659,8 @@ elif sys.version_info >= (3, 9):
         *,
         capture_output: bool = False,
         check: bool = False,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         input: ReadableBuffer | None = None,
         text: Literal[None, False] = ...,
         timeout: float | None = None,
@@ -838,8 +838,8 @@ else:
         *,
         capture_output: bool = False,
         check: bool = False,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         input: ReadableBuffer | None = None,
         text: Literal[None, False] = ...,
         timeout: float | None = None,
@@ -994,7 +994,7 @@ if sys.version_info >= (3, 11):
     def check_call(
         args: _CMD,
         bufsize: int = ...,
-        executable: StrOrBytesPath = ...,
+        executable: StrOrBytesPath | None = None,
         stdin: _FILE = ...,
         stdout: _FILE = ...,
         stderr: _FILE = ...,
@@ -1025,7 +1025,7 @@ elif sys.version_info >= (3, 10):
     def check_call(
         args: _CMD,
         bufsize: int = ...,
-        executable: StrOrBytesPath = ...,
+        executable: StrOrBytesPath | None = None,
         stdin: _FILE = ...,
         stdout: _FILE = ...,
         stderr: _FILE = ...,
@@ -1055,7 +1055,7 @@ elif sys.version_info >= (3, 9):
     def check_call(
         args: _CMD,
         bufsize: int = ...,
-        executable: StrOrBytesPath = ...,
+        executable: StrOrBytesPath | None = None,
         stdin: _FILE = ...,
         stdout: _FILE = ...,
         stderr: _FILE = ...,
@@ -1083,7 +1083,7 @@ else:
     def check_call(
         args: _CMD,
         bufsize: int = ...,
-        executable: StrOrBytesPath = ...,
+        executable: StrOrBytesPath | None = None,
         stdin: _FILE = ...,
         stdout: _FILE = ...,
         stderr: _FILE = ...,
@@ -1251,8 +1251,8 @@ if sys.version_info >= (3, 11):
         *,
         timeout: float | None = None,
         input: _InputString | None = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[None, False] = ...,
         user: str | int | None = ...,
         group: str | int | None = ...,
@@ -1437,8 +1437,8 @@ elif sys.version_info >= (3, 10):
         *,
         timeout: float | None = None,
         input: _InputString | None = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[None, False] = ...,
         user: str | int | None = ...,
         group: str | int | None = ...,
@@ -1617,8 +1617,8 @@ elif sys.version_info >= (3, 9):
         *,
         timeout: float | None = None,
         input: _InputString | None = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[None, False] = ...,
         user: str | int | None = ...,
         group: str | int | None = ...,
@@ -1778,8 +1778,8 @@ else:
         *,
         timeout: float | None = None,
         input: _InputString | None = ...,
-        encoding: None = ...,
-        errors: None = ...,
+        encoding: None = None,
+        errors: None = None,
         text: Literal[None, False] = ...,
     ) -> bytes: ...
     @overload
@@ -2560,7 +2560,7 @@ class Popen(Generic[AnyStr]):
     def send_signal(self, sig: int) -> None: ...
     def terminate(self) -> None: ...
     def kill(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/sunau.pyi b/mypy/typeshed/stdlib/sunau.pyi
index 7702443b0c1c..6109b368c01a 100644
--- a/mypy/typeshed/stdlib/sunau.pyi
+++ b/mypy/typeshed/stdlib/sunau.pyi
@@ -1,7 +1,7 @@
 import sys
-from _typeshed import Self, Unused
+from _typeshed import Unused
 from typing import IO, Any, NamedTuple, NoReturn, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 _File: TypeAlias = str | IO[bytes]
 
@@ -32,7 +32,7 @@ class _sunau_params(NamedTuple):
 
 class Au_read:
     def __init__(self, f: _File) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def getfp(self) -> IO[bytes] | None: ...
     def rewind(self) -> None: ...
@@ -52,7 +52,7 @@ class Au_read:
 
 class Au_write:
     def __init__(self, f: _File) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def setnchannels(self, nchannels: int) -> None: ...
     def getnchannels(self) -> int: ...
diff --git a/mypy/typeshed/stdlib/sys.pyi b/mypy/typeshed/stdlib/sys.pyi
index 725f66794cf6..e12881599b4a 100644
--- a/mypy/typeshed/stdlib/sys.pyi
+++ b/mypy/typeshed/stdlib/sys.pyi
@@ -7,7 +7,7 @@ from importlib.machinery import ModuleSpec
 from io import TextIOWrapper
 from types import FrameType, ModuleType, TracebackType
 from typing import Any, NoReturn, Protocol, TextIO, TypeVar, overload
-from typing_extensions import Literal, TypeAlias, final
+from typing_extensions import Final, Literal, TypeAlias, final
 
 _T = TypeVar("_T")
 
@@ -62,9 +62,10 @@ stdout: TextIO
 stderr: TextIO
 if sys.version_info >= (3, 10):
     stdlib_module_names: frozenset[str]
-__stdin__: TextIOWrapper
-__stdout__: TextIOWrapper
-__stderr__: TextIOWrapper
+
+__stdin__: Final[TextIOWrapper]  # Contains the original value of stdin
+__stdout__: Final[TextIOWrapper]  # Contains the original value of stdout
+__stderr__: Final[TextIOWrapper]  # Contains the original value of stderr
 tracebacklimit: int
 version: str
 api_version: int
@@ -277,11 +278,10 @@ if sys.platform == "win32":
 
 def intern(__string: str) -> str: ...
 def is_finalizing() -> bool: ...
-
-__breakpointhook__: Any  # contains the original value of breakpointhook
-
 def breakpointhook(*args: Any, **kwargs: Any) -> Any: ...
 
+__breakpointhook__ = breakpointhook  # Contains the original value of breakpointhook
+
 if sys.platform != "win32":
     def setdlopenflags(__flags: int) -> None: ...
 
diff --git a/mypy/typeshed/stdlib/tarfile.pyi b/mypy/typeshed/stdlib/tarfile.pyi
index 0aca7956a580..5cf1d55cac63 100644
--- a/mypy/typeshed/stdlib/tarfile.pyi
+++ b/mypy/typeshed/stdlib/tarfile.pyi
@@ -1,13 +1,13 @@
 import bz2
 import io
 import sys
-from _typeshed import Self, StrOrBytesPath, StrPath
-from builtins import list as _list, type as Type  # aliases to avoid name clashes with fields named "type" or "list"
+from _typeshed import StrOrBytesPath, StrPath
+from builtins import list as _list  # aliases to avoid name clashes with fields named "type" or "list"
 from collections.abc import Callable, Iterable, Iterator, Mapping
 from gzip import _ReadableFileobj as _GzipReadableFileobj, _WritableFileobj as _GzipWritableFileobj
 from types import TracebackType
 from typing import IO, ClassVar, Protocol, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 __all__ = [
     "TarFile",
@@ -141,14 +141,14 @@ class TarFile:
         errorlevel: int | None = None,
         copybufsize: int | None = None,  # undocumented
     ) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
     def __iter__(self) -> Iterator[TarInfo]: ...
     @classmethod
     def open(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None = None,
         mode: str = "r",
         fileobj: IO[bytes] | None = None,  # depends on mode
@@ -166,7 +166,7 @@ class TarFile:
     ) -> Self: ...
     @classmethod
     def taropen(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["r", "a", "w", "x"] = "r",
         fileobj: _Fileobj | None = None,
@@ -184,7 +184,7 @@ class TarFile:
     @overload
     @classmethod
     def gzopen(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["r"] = "r",
         fileobj: _GzipReadableFileobj | None = None,
@@ -202,7 +202,7 @@ class TarFile:
     @overload
     @classmethod
     def gzopen(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["w", "x"],
         fileobj: _GzipWritableFileobj | None = None,
@@ -220,7 +220,7 @@ class TarFile:
     @overload
     @classmethod
     def bz2open(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["w", "x"],
         fileobj: _Bz2WritableFileobj | None = None,
@@ -238,7 +238,7 @@ class TarFile:
     @overload
     @classmethod
     def bz2open(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["r"] = "r",
         fileobj: _Bz2ReadableFileobj | None = None,
@@ -255,7 +255,7 @@ class TarFile:
     ) -> Self: ...
     @classmethod
     def xzopen(
-        cls: type[Self],
+        cls,
         name: StrOrBytesPath | None,
         mode: Literal["r", "w", "x"] = "r",
         fileobj: IO[bytes] | None = None,
@@ -346,9 +346,9 @@ class TarInfo:
     pax_headers: Mapping[str, str]
     def __init__(self, name: str = "") -> None: ...
     @classmethod
-    def frombuf(cls: Type[Self], buf: bytes | bytearray, encoding: str, errors: str) -> Self: ...
+    def frombuf(cls, buf: bytes | bytearray, encoding: str, errors: str) -> Self: ...
     @classmethod
-    def fromtarfile(cls: Type[Self], tarfile: TarFile) -> Self: ...
+    def fromtarfile(cls, tarfile: TarFile) -> Self: ...
     @property
     def linkpath(self) -> str: ...
     @linkpath.setter
diff --git a/mypy/typeshed/stdlib/telnetlib.pyi b/mypy/typeshed/stdlib/telnetlib.pyi
index bcf9ef3693b2..10f6e4930f75 100644
--- a/mypy/typeshed/stdlib/telnetlib.pyi
+++ b/mypy/typeshed/stdlib/telnetlib.pyi
@@ -1,9 +1,9 @@
 import socket
-from _typeshed import Self
 from collections.abc import Callable, Sequence
 from re import Match, Pattern
 from types import TracebackType
 from typing import Any
+from typing_extensions import Self
 
 __all__ = ["Telnet"]
 
@@ -115,7 +115,7 @@ class Telnet:
     def expect(
         self, list: Sequence[Pattern[bytes] | bytes], timeout: float | None = None
     ) -> tuple[int, Match[bytes] | None, bytes]: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/tempfile.pyi b/mypy/typeshed/stdlib/tempfile.pyi
index 9dc23be2557f..dbff6d632d02 100644
--- a/mypy/typeshed/stdlib/tempfile.pyi
+++ b/mypy/typeshed/stdlib/tempfile.pyi
@@ -1,10 +1,10 @@
 import io
 import sys
-from _typeshed import BytesPath, GenericPath, Self, StrPath, WriteableBuffer
+from _typeshed import BytesPath, GenericPath, StrPath, WriteableBuffer
 from collections.abc import Iterable, Iterator
 from types import TracebackType
 from typing import IO, Any, AnyStr, Generic, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -186,7 +186,7 @@ class _TemporaryFileWrapper(Generic[AnyStr], IO[AnyStr]):
     name: str
     delete: bool
     def __init__(self, file: IO[AnyStr], name: str, delete: bool = True) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, exc: type[BaseException] | None, value: BaseException | None, tb: TracebackType | None) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
     def close(self) -> None: ...
@@ -369,7 +369,7 @@ class SpooledTemporaryFile(IO[AnyStr], _SpooledTemporaryFileBase):
         ) -> None: ...
 
     def rollover(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, exc: type[BaseException] | None, value: BaseException | None, tb: TracebackType | None) -> None: ...
     # These methods are copied from the abstract methods of IO, because
     # SpooledTemporaryFile implements IO.
diff --git a/mypy/typeshed/stdlib/tkinter/__init__.pyi b/mypy/typeshed/stdlib/tkinter/__init__.pyi
index fdacf0097008..1d30e4b73c23 100644
--- a/mypy/typeshed/stdlib/tkinter/__init__.pyi
+++ b/mypy/typeshed/stdlib/tkinter/__init__.pyi
@@ -6,7 +6,7 @@ from enum import Enum
 from tkinter.constants import *
 from tkinter.font import _FontDescription
 from types import TracebackType
-from typing import Any, Generic, NamedTuple, Protocol, TypeVar, Union, overload
+from typing import Any, Generic, NamedTuple, Protocol, TypeVar, overload
 from typing_extensions import Literal, TypeAlias, TypedDict
 
 if sys.version_info >= (3, 9):
@@ -179,7 +179,7 @@ _CanvasItemId: TypeAlias = int
 _Color: TypeAlias = str  # typically '#rrggbb', '#rgb' or color names.
 _Compound: TypeAlias = Literal["top", "left", "center", "right", "bottom", "none"]  # -compound in manual page named 'options'
 # manual page: Tk_GetCursor
-_Cursor: TypeAlias = Union[str, tuple[str], tuple[str, str], tuple[str, str, str], tuple[str, str, str, str]]
+_Cursor: TypeAlias = str | tuple[str] | tuple[str, str] | tuple[str, str, str] | tuple[str, str, str, str]
 # example when it's sequence:  entry['invalidcommand'] = [entry.register(print), '%P']
 _EntryValidateCommand: TypeAlias = str | list[str] | tuple[str, ...] | Callable[[], bool]
 _GridIndex: TypeAlias = int | str
@@ -188,7 +188,7 @@ _Relief: TypeAlias = Literal["raised", "sunken", "flat", "ridge", "solid", "groo
 _ScreenUnits: TypeAlias = str | float  # Often the right type instead of int. Manual page: Tk_GetPixels
 # -xscrollcommand and -yscrollcommand in 'options' manual page
 _XYScrollCommand: TypeAlias = str | Callable[[float, float], object]
-_TakeFocusValue: TypeAlias = Union[int, Literal[""], Callable[[str], bool | None]]  # -takefocus in manual page named 'options'
+_TakeFocusValue: TypeAlias = int | Literal[""] | Callable[[str], bool | None]  # -takefocus in manual page named 'options'
 
 if sys.version_info >= (3, 11):
     class _VersionInfoType(NamedTuple):
@@ -421,7 +421,7 @@ class Misc:
     def winfo_viewable(self) -> bool: ...
     def winfo_visual(self) -> str: ...
     def winfo_visualid(self) -> str: ...
-    def winfo_visualsavailable(self, includeids: int = False) -> list[tuple[str, int]]: ...
+    def winfo_visualsavailable(self, includeids: bool = False) -> list[tuple[str, int]]: ...
     def winfo_vrootheight(self) -> int: ...
     def winfo_vrootwidth(self) -> int: ...
     def winfo_vrootx(self) -> int: ...
diff --git a/mypy/typeshed/stdlib/tkinter/ttk.pyi b/mypy/typeshed/stdlib/tkinter/ttk.pyi
index bd477535f41f..61ebc0e2734f 100644
--- a/mypy/typeshed/stdlib/tkinter/ttk.pyi
+++ b/mypy/typeshed/stdlib/tkinter/ttk.pyi
@@ -4,7 +4,7 @@ import tkinter
 from _typeshed import Incomplete
 from collections.abc import Callable
 from tkinter.font import _FontDescription
-from typing import Any, Union, overload
+from typing import Any, overload
 from typing_extensions import Literal, TypeAlias, TypedDict
 
 __all__ = [
@@ -38,13 +38,13 @@ __all__ = [
 def tclobjs_to_py(adict: dict[Any, Any]) -> dict[Any, Any]: ...
 def setup_master(master: Incomplete | None = None): ...
 
-_Padding: TypeAlias = Union[
-    tkinter._ScreenUnits,
-    tuple[tkinter._ScreenUnits],
-    tuple[tkinter._ScreenUnits, tkinter._ScreenUnits],
-    tuple[tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits],
-    tuple[tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits],
-]
+_Padding: TypeAlias = (
+    tkinter._ScreenUnits
+    | tuple[tkinter._ScreenUnits]
+    | tuple[tkinter._ScreenUnits, tkinter._ScreenUnits]
+    | tuple[tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits]
+    | tuple[tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits, tkinter._ScreenUnits]
+)
 
 # from ttk_widget (aka ttk::widget) manual page, differs from tkinter._Compound
 _TtkCompound: TypeAlias = Literal["text", "image", tkinter._Compound]
diff --git a/mypy/typeshed/stdlib/traceback.pyi b/mypy/typeshed/stdlib/traceback.pyi
index cdda50c0a1b3..4483a8c2a1b0 100644
--- a/mypy/typeshed/stdlib/traceback.pyi
+++ b/mypy/typeshed/stdlib/traceback.pyi
@@ -1,9 +1,9 @@
 import sys
-from _typeshed import Self, SupportsWrite
+from _typeshed import SupportsWrite
 from collections.abc import Generator, Iterable, Iterator, Mapping
 from types import FrameType, TracebackType
 from typing import Any, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = [
     "extract_stack",
@@ -129,7 +129,7 @@ class TracebackException:
         ) -> None: ...
         @classmethod
         def from_exception(
-            cls: type[Self],
+            cls,
             exc: BaseException,
             *,
             limit: int | None = ...,
@@ -154,7 +154,7 @@ class TracebackException:
         ) -> None: ...
         @classmethod
         def from_exception(
-            cls: type[Self],
+            cls,
             exc: BaseException,
             *,
             limit: int | None = ...,
@@ -176,7 +176,7 @@ class TracebackException:
         ) -> None: ...
         @classmethod
         def from_exception(
-            cls: type[Self], exc: BaseException, *, limit: int | None = ..., lookup_lines: bool = ..., capture_locals: bool = ...
+            cls, exc: BaseException, *, limit: int | None = ..., lookup_lines: bool = ..., capture_locals: bool = ...
         ) -> Self: ...
 
     def __eq__(self, other: object) -> bool: ...
diff --git a/mypy/typeshed/stdlib/tracemalloc.pyi b/mypy/typeshed/stdlib/tracemalloc.pyi
index d7214de285f8..3dc8b8603fe5 100644
--- a/mypy/typeshed/stdlib/tracemalloc.pyi
+++ b/mypy/typeshed/stdlib/tracemalloc.pyi
@@ -1,7 +1,7 @@
 import sys
 from _tracemalloc import *
 from collections.abc import Sequence
-from typing import Any, Union, overload
+from typing import Any, overload
 from typing_extensions import SupportsIndex, TypeAlias
 
 def get_object_traceback(obj: object) -> Traceback | None: ...
@@ -67,7 +67,7 @@ class Frame:
         def __le__(self, other: Frame, NotImplemented: Any = ...) -> bool: ...
 
 if sys.version_info >= (3, 9):
-    _TraceTuple: TypeAlias = Union[tuple[int, int, Sequence[_FrameTuple], int | None], tuple[int, int, Sequence[_FrameTuple]]]
+    _TraceTuple: TypeAlias = tuple[int, int, Sequence[_FrameTuple], int | None] | tuple[int, int, Sequence[_FrameTuple]]
 else:
     _TraceTuple: TypeAlias = tuple[int, int, Sequence[_FrameTuple]]
 
diff --git a/mypy/typeshed/stdlib/turtle.pyi b/mypy/typeshed/stdlib/turtle.pyi
index 1259ca6fb4cc..8017c8290fb9 100644
--- a/mypy/typeshed/stdlib/turtle.pyi
+++ b/mypy/typeshed/stdlib/turtle.pyi
@@ -1,8 +1,7 @@
-from _typeshed import Self
 from collections.abc import Callable, Sequence
 from tkinter import Canvas, Frame, Misc, PhotoImage, Scrollbar
-from typing import Any, ClassVar, Union, overload
-from typing_extensions import TypeAlias
+from typing import Any, ClassVar, overload
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "ScrolledCanvas",
@@ -133,7 +132,7 @@ __all__ = [
 # alias we use for return types. Really, these two aliases should be the
 # same, but as per the "no union returns" typeshed policy, we'll return
 # Any instead.
-_Color: TypeAlias = Union[str, tuple[float, float, float]]
+_Color: TypeAlias = str | tuple[float, float, float]
 _AnyColor: TypeAlias = Any
 
 # TODO: Replace this with a TypedDict once it becomes standardized.
@@ -143,7 +142,7 @@ _Speed: TypeAlias = str | float
 _PolygonCoords: TypeAlias = Sequence[tuple[float, float]]
 
 class Vec2D(tuple[float, float]):
-    def __new__(cls: type[Self], x: float, y: float) -> Self: ...
+    def __new__(cls, x: float, y: float) -> Self: ...
     def __add__(self, other: tuple[float, float]) -> Vec2D: ...  # type: ignore[override]
     @overload  # type: ignore[override]
     def __mul__(self, other: Vec2D) -> float: ...
@@ -366,7 +365,7 @@ class RawTurtle(TPen, TNavigator):
     def setundobuffer(self, size: int | None) -> None: ...
     def undobufferentries(self) -> int: ...
     def clear(self) -> None: ...
-    def clone(self: Self) -> Self: ...
+    def clone(self) -> Self: ...
     @overload
     def shape(self, name: None = None) -> str: ...
     @overload
@@ -411,7 +410,7 @@ class RawTurtle(TPen, TNavigator):
     def end_poly(self) -> None: ...
     def get_poly(self) -> _PolygonCoords | None: ...
     def getscreen(self) -> TurtleScreen: ...
-    def getturtle(self: Self) -> Self: ...
+    def getturtle(self) -> Self: ...
     getpen = getturtle
     def onclick(self, fun: Callable[[float, float], object], btn: int = 1, add: bool | None = None) -> None: ...
     def onrelease(self, fun: Callable[[float, float], object], btn: int = 1, add: bool | None = None) -> None: ...
diff --git a/mypy/typeshed/stdlib/types.pyi b/mypy/typeshed/stdlib/types.pyi
index 5fb24106685e..d529b3d9ad1a 100644
--- a/mypy/typeshed/stdlib/types.pyi
+++ b/mypy/typeshed/stdlib/types.pyi
@@ -363,7 +363,7 @@ class GeneratorType(Generator[_T_co, _T_contra, _V_co]):
         self, __typ: type[BaseException], __val: BaseException | object = ..., __tb: TracebackType | None = ...
     ) -> _T_co: ...
     @overload
-    def throw(self, __typ: BaseException, __val: None = ..., __tb: TracebackType | None = ...) -> _T_co: ...
+    def throw(self, __typ: BaseException, __val: None = None, __tb: TracebackType | None = ...) -> _T_co: ...
 
 @final
 class AsyncGeneratorType(AsyncGenerator[_T_co, _T_contra]):
@@ -379,7 +379,7 @@ class AsyncGeneratorType(AsyncGenerator[_T_co, _T_contra]):
         self, __typ: type[BaseException], __val: BaseException | object = ..., __tb: TracebackType | None = ...
     ) -> _T_co: ...
     @overload
-    async def athrow(self, __typ: BaseException, __val: None = ..., __tb: TracebackType | None = ...) -> _T_co: ...
+    async def athrow(self, __typ: BaseException, __val: None = None, __tb: TracebackType | None = ...) -> _T_co: ...
     def aclose(self) -> Coroutine[Any, Any, None]: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
@@ -402,7 +402,7 @@ class CoroutineType(Coroutine[_T_co, _T_contra, _V_co]):
         self, __typ: type[BaseException], __val: BaseException | object = ..., __tb: TracebackType | None = ...
     ) -> _T_co: ...
     @overload
-    def throw(self, __typ: BaseException, __val: None = ..., __tb: TracebackType | None = ...) -> _T_co: ...
+    def throw(self, __typ: BaseException, __val: None = None, __tb: TracebackType | None = ...) -> _T_co: ...
 
 class _StaticFunctionType:
     # Fictional type to correct the type of MethodType.__func__.
diff --git a/mypy/typeshed/stdlib/typing.pyi b/mypy/typeshed/stdlib/typing.pyi
index eaa566582fb4..d06b081d3ddc 100644
--- a/mypy/typeshed/stdlib/typing.pyi
+++ b/mypy/typeshed/stdlib/typing.pyi
@@ -1,6 +1,6 @@
-import _typeshed
 import collections  # Needed by aliases like DefaultDict, see mypy issue 2986
 import sys
+import typing_extensions
 from _collections_abc import dict_items, dict_keys, dict_values
 from _typeshed import IdentityFunction, Incomplete, SupportsKeysAndGetItem
 from abc import ABCMeta, abstractmethod
@@ -501,7 +501,7 @@ class MutableSequence(Sequence[_T], Generic[_T]):
     def reverse(self) -> None: ...
     def pop(self, index: int = -1) -> _T: ...
     def remove(self, value: _T) -> None: ...
-    def __iadd__(self: _typeshed.Self, values: Iterable[_T]) -> _typeshed.Self: ...
+    def __iadd__(self, values: Iterable[_T]) -> typing_extensions.Self: ...
 
 class AbstractSet(Collection[_T_co], Generic[_T_co]):
     @abstractmethod
@@ -527,10 +527,10 @@ class MutableSet(AbstractSet[_T], Generic[_T]):
     def clear(self) -> None: ...
     def pop(self) -> _T: ...
     def remove(self, value: _T) -> None: ...
-    def __ior__(self: _typeshed.Self, it: AbstractSet[_T]) -> _typeshed.Self: ...  # type: ignore[override,misc]
-    def __iand__(self: _typeshed.Self, it: AbstractSet[Any]) -> _typeshed.Self: ...
-    def __ixor__(self: _typeshed.Self, it: AbstractSet[_T]) -> _typeshed.Self: ...  # type: ignore[override,misc]
-    def __isub__(self: _typeshed.Self, it: AbstractSet[Any]) -> _typeshed.Self: ...
+    def __ior__(self, it: AbstractSet[_T]) -> typing_extensions.Self: ...  # type: ignore[override,misc]
+    def __iand__(self, it: AbstractSet[Any]) -> typing_extensions.Self: ...
+    def __ixor__(self, it: AbstractSet[_T]) -> typing_extensions.Self: ...  # type: ignore[override,misc]
+    def __isub__(self, it: AbstractSet[Any]) -> typing_extensions.Self: ...
 
 class MappingView(Sized):
     def __init__(self, mapping: Mapping[Any, Any]) -> None: ...  # undocumented
@@ -719,7 +719,7 @@ class ByteString(Sequence[int], metaclass=ABCMeta): ...
 
 # Functions
 
-_get_type_hints_obj_allowed_types = (  # noqa: Y026  # TODO: Use TypeAlias once mypy bugs are fixed
+_get_type_hints_obj_allowed_types: typing_extensions.TypeAlias = (  # noqa: Y042
     object
     | Callable[..., Any]
     | FunctionType
@@ -783,7 +783,7 @@ class NamedTuple(tuple[Any, ...]):
     @overload
     def __init__(self, typename: str, fields: Iterable[tuple[str, Any]] = ...) -> None: ...
     @overload
-    def __init__(self, typename: str, fields: None = ..., **kwargs: Any) -> None: ...
+    def __init__(self, typename: str, fields: None = None, **kwargs: Any) -> None: ...
     @classmethod
     def _make(cls: Type[_T], iterable: Iterable[Any]) -> _T: ...
     if sys.version_info >= (3, 8):
@@ -791,7 +791,7 @@ class NamedTuple(tuple[Any, ...]):
     else:
         def _asdict(self) -> collections.OrderedDict[str, Any]: ...
 
-    def _replace(self: _typeshed.Self, **kwargs: Any) -> _typeshed.Self: ...
+    def _replace(self, **kwargs: Any) -> typing_extensions.Self: ...
 
 # Internal mypy fallback type for all typed dicts (does not exist at runtime)
 # N.B. Keep this mostly in sync with typing_extensions._TypedDict/mypy_extensions._TypedDict
@@ -801,7 +801,7 @@ class _TypedDict(Mapping[str, object], metaclass=ABCMeta):
     if sys.version_info >= (3, 9):
         __required_keys__: ClassVar[frozenset[str]]
         __optional_keys__: ClassVar[frozenset[str]]
-    def copy(self: _typeshed.Self) -> _typeshed.Self: ...
+    def copy(self) -> typing_extensions.Self: ...
     # Using Never so that only calls using mypy plugin hook that specialize the signature
     # can go through.
     def setdefault(self, k: _Never, default: object) -> object: ...
@@ -813,8 +813,8 @@ class _TypedDict(Mapping[str, object], metaclass=ABCMeta):
     def keys(self) -> dict_keys[str, object]: ...
     def values(self) -> dict_values[str, object]: ...
     if sys.version_info >= (3, 9):
-        def __or__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
-        def __ior__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
+        def __or__(self, __value: typing_extensions.Self) -> typing_extensions.Self: ...
+        def __ior__(self, __value: typing_extensions.Self) -> typing_extensions.Self: ...
 
 @_final
 class ForwardRef:
diff --git a/mypy/typeshed/stdlib/typing_extensions.pyi b/mypy/typeshed/stdlib/typing_extensions.pyi
index 73a41f16600d..bf3892d5709e 100644
--- a/mypy/typeshed/stdlib/typing_extensions.pyi
+++ b/mypy/typeshed/stdlib/typing_extensions.pyi
@@ -1,4 +1,3 @@
-import _typeshed
 import abc
 import collections
 import sys
@@ -129,7 +128,7 @@ class _TypedDict(Mapping[str, object], metaclass=abc.ABCMeta):
     __required_keys__: ClassVar[frozenset[str]]
     __optional_keys__: ClassVar[frozenset[str]]
     __total__: ClassVar[bool]
-    def copy(self: _typeshed.Self) -> _typeshed.Self: ...
+    def copy(self) -> Self: ...
     # Using Never so that only calls using mypy plugin hook that specialize the signature
     # can go through.
     def setdefault(self, k: Never, default: object) -> object: ...
@@ -141,8 +140,8 @@ class _TypedDict(Mapping[str, object], metaclass=abc.ABCMeta):
     def values(self) -> dict_values[str, object]: ...
     def __delitem__(self, k: Never) -> None: ...
     if sys.version_info >= (3, 9):
-        def __or__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
-        def __ior__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
+        def __or__(self, __value: Self) -> Self: ...
+        def __ior__(self, __value: Self) -> Self: ...
 
 # TypedDict is a (non-subscriptable) special form.
 TypedDict: object
@@ -242,15 +241,15 @@ else:
         @overload
         def __init__(self, typename: str, fields: Iterable[tuple[str, Any]] = ...) -> None: ...
         @overload
-        def __init__(self, typename: str, fields: None = ..., **kwargs: Any) -> None: ...
+        def __init__(self, typename: str, fields: None = None, **kwargs: Any) -> None: ...
         @classmethod
-        def _make(cls: type[_typeshed.Self], iterable: Iterable[Any]) -> _typeshed.Self: ...
+        def _make(cls, iterable: Iterable[Any]) -> Self: ...
         if sys.version_info >= (3, 8):
             def _asdict(self) -> dict[str, Any]: ...
         else:
             def _asdict(self) -> collections.OrderedDict[str, Any]: ...
 
-        def _replace(self: _typeshed.Self, **kwargs: Any) -> _typeshed.Self: ...
+        def _replace(self, **kwargs: Any) -> Self: ...
 
 # New things in 3.xx
 # The `default` parameter was added to TypeVar, ParamSpec, and TypeVarTuple (PEP 696)
diff --git a/mypy/typeshed/stdlib/unicodedata.pyi b/mypy/typeshed/stdlib/unicodedata.pyi
index 4569d6584fd6..5a1f7fe6638d 100644
--- a/mypy/typeshed/stdlib/unicodedata.pyi
+++ b/mypy/typeshed/stdlib/unicodedata.pyi
@@ -1,6 +1,6 @@
 import sys
 from _typeshed import ReadOnlyBuffer
-from typing import Any, TypeVar
+from typing import Any, TypeVar, overload
 from typing_extensions import Literal, TypeAlias, final
 
 ucd_3_2_0: UCD
@@ -14,9 +14,15 @@ _T = TypeVar("_T")
 def bidirectional(__chr: str) -> str: ...
 def category(__chr: str) -> str: ...
 def combining(__chr: str) -> int: ...
-def decimal(__chr: str, __default: _T = ...) -> int | _T: ...
+@overload
+def decimal(__chr: str) -> int: ...
+@overload
+def decimal(__chr: str, __default: _T) -> int | _T: ...
 def decomposition(__chr: str) -> str: ...
-def digit(__chr: str, __default: _T = ...) -> int | _T: ...
+@overload
+def digit(__chr: str) -> int: ...
+@overload
+def digit(__chr: str, __default: _T) -> int | _T: ...
 
 _EastAsianWidth: TypeAlias = Literal["F", "H", "W", "Na", "A", "N"]
 
@@ -27,26 +33,44 @@ if sys.version_info >= (3, 8):
 
 def lookup(__name: str | ReadOnlyBuffer) -> str: ...
 def mirrored(__chr: str) -> int: ...
-def name(__chr: str, __default: _T = ...) -> str | _T: ...
+@overload
+def name(__chr: str) -> str: ...
+@overload
+def name(__chr: str, __default: _T) -> str | _T: ...
 def normalize(__form: str, __unistr: str) -> str: ...
-def numeric(__chr: str, __default: _T = ...) -> float | _T: ...
+@overload
+def numeric(__chr: str) -> float: ...
+@overload
+def numeric(__chr: str, __default: _T) -> float | _T: ...
 @final
 class UCD:
     # The methods below are constructed from the same array in C
-    # (unicodedata_functions) and hence identical to the methods above.
+    # (unicodedata_functions) and hence identical to the functions above.
     unidata_version: str
     def bidirectional(self, __chr: str) -> str: ...
     def category(self, __chr: str) -> str: ...
     def combining(self, __chr: str) -> int: ...
-    def decimal(self, __chr: str, __default: _T = ...) -> int | _T: ...
+    @overload
+    def decimal(self, __chr: str) -> int: ...
+    @overload
+    def decimal(self, __chr: str, __default: _T) -> int | _T: ...
     def decomposition(self, __chr: str) -> str: ...
-    def digit(self, __chr: str, __default: _T = ...) -> int | _T: ...
+    @overload
+    def digit(self, __chr: str) -> int: ...
+    @overload
+    def digit(self, __chr: str, __default: _T) -> int | _T: ...
     def east_asian_width(self, __chr: str) -> _EastAsianWidth: ...
     if sys.version_info >= (3, 8):
         def is_normalized(self, __form: str, __unistr: str) -> bool: ...
 
     def lookup(self, __name: str | ReadOnlyBuffer) -> str: ...
     def mirrored(self, __chr: str) -> int: ...
-    def name(self, __chr: str, __default: _T = ...) -> str | _T: ...
+    @overload
+    def name(self, __chr: str) -> str: ...
+    @overload
+    def name(self, __chr: str, __default: _T) -> str | _T: ...
     def normalize(self, __form: str, __unistr: str) -> str: ...
-    def numeric(self, __chr: str, __default: _T = ...) -> float | _T: ...
+    @overload
+    def numeric(self, __chr: str) -> float: ...
+    @overload
+    def numeric(self, __chr: str, __default: _T) -> float | _T: ...
diff --git a/mypy/typeshed/stdlib/unittest/case.pyi b/mypy/typeshed/stdlib/unittest/case.pyi
index 5b1bd9288659..8f8cf43385a8 100644
--- a/mypy/typeshed/stdlib/unittest/case.pyi
+++ b/mypy/typeshed/stdlib/unittest/case.pyi
@@ -1,26 +1,13 @@
 import logging
 import sys
 import unittest.result
-from _typeshed import Self, SupportsDunderGE, SupportsDunderGT, SupportsDunderLE, SupportsDunderLT, SupportsRSub, SupportsSub
+from _typeshed import SupportsDunderGE, SupportsDunderGT, SupportsDunderLE, SupportsDunderLT, SupportsRSub, SupportsSub
 from collections.abc import Callable, Container, Iterable, Mapping, Sequence, Set as AbstractSet
 from contextlib import AbstractContextManager
 from re import Pattern
 from types import TracebackType
-from typing import (
-    Any,
-    AnyStr,
-    ClassVar,
-    Generic,
-    NamedTuple,
-    NoReturn,
-    Protocol,
-    SupportsAbs,
-    SupportsRound,
-    TypeVar,
-    Union,
-    overload,
-)
-from typing_extensions import ParamSpec, TypeAlias
+from typing import Any, AnyStr, ClassVar, Generic, NamedTuple, NoReturn, Protocol, SupportsAbs, SupportsRound, TypeVar, overload
+from typing_extensions import ParamSpec, Self, TypeAlias
 from warnings import WarningMessage
 
 if sys.version_info >= (3, 9):
@@ -82,9 +69,9 @@ class SkipTest(Exception):
 class _SupportsAbsAndDunderGE(SupportsDunderGE[Any], SupportsAbs[Any], Protocol): ...
 
 if sys.version_info >= (3, 10):
-    _IsInstanceClassInfo: TypeAlias = Union[type, UnionType, tuple[type | UnionType | tuple[Any, ...], ...]]
+    _IsInstanceClassInfo: TypeAlias = type | UnionType | tuple[type | UnionType | tuple[Any, ...], ...]
 else:
-    _IsInstanceClassInfo: TypeAlias = Union[type, tuple[type | tuple[Any, ...], ...]]
+    _IsInstanceClassInfo: TypeAlias = type | tuple[type | tuple[Any, ...], ...]
 
 class TestCase:
     failureException: type[BaseException]
@@ -317,7 +304,7 @@ class FunctionTestCase(TestCase):
 
 class _AssertRaisesContext(Generic[_E]):
     exception: _E
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, tb: TracebackType | None
     ) -> bool: ...
@@ -329,7 +316,7 @@ class _AssertWarnsContext:
     filename: str
     lineno: int
     warnings: list[WarningMessage]
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/unittest/mock.pyi b/mypy/typeshed/stdlib/unittest/mock.pyi
index 54c79fd433d2..f0345c903a3b 100644
--- a/mypy/typeshed/stdlib/unittest/mock.pyi
+++ b/mypy/typeshed/stdlib/unittest/mock.pyi
@@ -1,10 +1,9 @@
 import sys
-from _typeshed import Self
 from collections.abc import Awaitable, Callable, Coroutine, Iterable, Mapping, Sequence
 from contextlib import _GeneratorContextManager
 from types import TracebackType
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Final, Literal, Self, TypeAlias
 
 _T = TypeVar("_T")
 _TT = TypeVar("_TT", bound=type[Any])
@@ -48,7 +47,7 @@ else:
         "seal",
     )
 
-__version__: str
+__version__: Final[str]
 
 FILTER_DIR: Any
 
@@ -68,12 +67,7 @@ _CallValue: TypeAlias = str | tuple[Any, ...] | Mapping[str, Any] | _ArgsKwargs
 
 class _Call(tuple[Any, ...]):
     def __new__(
-        cls: type[Self],
-        value: _CallValue = ...,
-        name: str | None = "",
-        parent: Any | None = None,
-        two: bool = False,
-        from_kall: bool = True,
+        cls, value: _CallValue = ..., name: str | None = "", parent: Any | None = None, two: bool = False, from_kall: bool = True
     ) -> Self: ...
     name: Any
     parent: Any
@@ -107,8 +101,10 @@ class _CallList(list[_Call]):
 class Base:
     def __init__(self, *args: Any, **kwargs: Any) -> None: ...
 
+# We subclass with "Any" because mocks are explicitly designed to stand in for other types,
+# something that can't be expressed with our static type system.
 class NonCallableMock(Base, Any):
-    def __new__(__cls: type[Self], *args: Any, **kw: Any) -> Self: ...
+    def __new__(__cls, *args: Any, **kw: Any) -> Self: ...
     def __init__(
         self,
         spec: list[str] | object | type[object] | None = None,
@@ -437,9 +433,9 @@ def mock_open(mock: Any | None = None, read_data: Any = "") -> Any: ...
 
 class PropertyMock(Mock):
     if sys.version_info >= (3, 8):
-        def __get__(self: Self, obj: _T, obj_type: type[_T] | None = None) -> Self: ...
+        def __get__(self, obj: _T, obj_type: type[_T] | None = None) -> Self: ...
     else:
-        def __get__(self: Self, obj: _T, obj_type: type[_T] | None) -> Self: ...
+        def __get__(self, obj: _T, obj_type: type[_T] | None) -> Self: ...
 
     def __set__(self, obj: Any, value: Any) -> None: ...
 
diff --git a/mypy/typeshed/stdlib/urllib/error.pyi b/mypy/typeshed/stdlib/urllib/error.pyi
index 8ea25680f1a4..89cec9bf289c 100644
--- a/mypy/typeshed/stdlib/urllib/error.pyi
+++ b/mypy/typeshed/stdlib/urllib/error.pyi
@@ -4,13 +4,15 @@ from urllib.response import addinfourl
 
 __all__ = ["URLError", "HTTPError", "ContentTooShortError"]
 
-class URLError(IOError):
+class URLError(OSError):
     reason: str | BaseException
     def __init__(self, reason: str | BaseException, filename: str | None = None) -> None: ...
 
 class HTTPError(URLError, addinfourl):
     @property
-    def headers(self) -> Message: ...  # type: ignore[override]
+    def headers(self) -> Message: ...
+    @headers.setter
+    def headers(self, headers: Message) -> None: ...
     @property
     def reason(self) -> str: ...  # type: ignore[override]
     code: int
diff --git a/mypy/typeshed/stdlib/urllib/response.pyi b/mypy/typeshed/stdlib/urllib/response.pyi
index 4db1b5649c7a..61ba687076b2 100644
--- a/mypy/typeshed/stdlib/urllib/response.pyi
+++ b/mypy/typeshed/stdlib/urllib/response.pyi
@@ -1,20 +1,21 @@
 import sys
-from _typeshed import ReadableBuffer, Self
+from _typeshed import ReadableBuffer
 from collections.abc import Callable, Iterable
 from email.message import Message
 from types import TracebackType
 from typing import IO, Any, BinaryIO
+from typing_extensions import Self
 
 __all__ = ["addbase", "addclosehook", "addinfo", "addinfourl"]
 
 class addbase(BinaryIO):
     fp: IO[bytes]
     def __init__(self, fp: IO[bytes]) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
-    def __iter__(self: Self) -> Self: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> bytes: ...
     def close(self) -> None: ...
     # These methods don't actually exist, but the class inherits at runtime from
diff --git a/mypy/typeshed/stdlib/uu.pyi b/mypy/typeshed/stdlib/uu.pyi
index 20e79bf3fec9..324053e04337 100644
--- a/mypy/typeshed/stdlib/uu.pyi
+++ b/mypy/typeshed/stdlib/uu.pyi
@@ -10,4 +10,4 @@ class Error(Exception): ...
 def encode(
     in_file: _File, out_file: _File, name: str | None = None, mode: int | None = None, *, backtick: bool = False
 ) -> None: ...
-def decode(in_file: _File, out_file: _File | None = None, mode: int | None = None, quiet: int = False) -> None: ...
+def decode(in_file: _File, out_file: _File | None = None, mode: int | None = None, quiet: bool = False) -> None: ...
diff --git a/mypy/typeshed/stdlib/wave.pyi b/mypy/typeshed/stdlib/wave.pyi
index 3817ae09307f..0d004d6b2d8a 100644
--- a/mypy/typeshed/stdlib/wave.pyi
+++ b/mypy/typeshed/stdlib/wave.pyi
@@ -1,7 +1,7 @@
 import sys
-from _typeshed import ReadableBuffer, Self, Unused
+from _typeshed import ReadableBuffer, Unused
 from typing import IO, Any, BinaryIO, NamedTuple, NoReturn, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 if sys.version_info >= (3, 9):
     __all__ = ["open", "Error", "Wave_read", "Wave_write"]
@@ -24,7 +24,7 @@ class _wave_params(NamedTuple):
 
 class Wave_read:
     def __init__(self, f: _File) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def getfp(self) -> BinaryIO | None: ...
     def rewind(self) -> None: ...
@@ -44,7 +44,7 @@ class Wave_read:
 
 class Wave_write:
     def __init__(self, f: _File) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def setnchannels(self, nchannels: int) -> None: ...
     def getnchannels(self) -> int: ...
diff --git a/mypy/typeshed/stdlib/weakref.pyi b/mypy/typeshed/stdlib/weakref.pyi
index a0f35b4f51eb..1e0aac814dfb 100644
--- a/mypy/typeshed/stdlib/weakref.pyi
+++ b/mypy/typeshed/stdlib/weakref.pyi
@@ -1,5 +1,5 @@
 import sys
-from _typeshed import Self, SupportsKeysAndGetItem
+from _typeshed import SupportsKeysAndGetItem
 from _weakref import (
     CallableProxyType as CallableProxyType,
     ProxyType as ProxyType,
@@ -12,7 +12,7 @@ from _weakref import (
 from _weakrefset import WeakSet as WeakSet
 from collections.abc import Callable, Iterable, Iterator, Mapping, MutableMapping
 from typing import Any, Generic, TypeVar, overload
-from typing_extensions import ParamSpec
+from typing_extensions import ParamSpec, Self
 
 __all__ = [
     "ref",
@@ -41,7 +41,7 @@ _P = ParamSpec("_P")
 ProxyTypes: tuple[type[Any], ...]
 
 class WeakMethod(ref[_CallableT], Generic[_CallableT]):
-    def __new__(cls: type[Self], meth: _CallableT, callback: Callable[[_CallableT], object] | None = None) -> Self: ...
+    def __new__(cls, meth: _CallableT, callback: Callable[[_CallableT], object] | None = None) -> Self: ...
     def __call__(self) -> _CallableT | None: ...
     def __eq__(self, other: object) -> bool: ...
     def __ne__(self, other: object) -> bool: ...
@@ -63,7 +63,7 @@ class WeakValueDictionary(MutableMapping[_KT, _VT]):
     def __iter__(self) -> Iterator[_KT]: ...
     def copy(self) -> WeakValueDictionary[_KT, _VT]: ...
     __copy__ = copy
-    def __deepcopy__(self: Self, memo: Any) -> Self: ...
+    def __deepcopy__(self, memo: Any) -> Self: ...
     # These are incompatible with Mapping
     def keys(self) -> Iterator[_KT]: ...  # type: ignore[override]
     def values(self) -> Iterator[_VT]: ...  # type: ignore[override]
@@ -80,14 +80,14 @@ class WeakValueDictionary(MutableMapping[_KT, _VT]):
         def __ror__(self, other: Mapping[_T1, _T2]) -> WeakValueDictionary[_KT | _T1, _VT | _T2]: ...
         # WeakValueDictionary.__ior__ should be kept roughly in line with MutableMapping.update()
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
+        def __ior__(self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
         @overload
-        def __ior__(self: Self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
+        def __ior__(self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
 
 class KeyedRef(ref[_T], Generic[_KT, _T]):
     key: _KT
     # This __new__ method uses a non-standard name for the "cls" parameter
-    def __new__(type: type[Self], ob: _T, callback: Callable[[_T], Any], key: _KT) -> Self: ...
+    def __new__(type, ob: _T, callback: Callable[[_T], Any], key: _KT) -> Self: ...
     def __init__(self, ob: _T, callback: Callable[[_T], Any], key: _KT) -> None: ...
 
 class WeakKeyDictionary(MutableMapping[_KT, _VT]):
@@ -103,7 +103,7 @@ class WeakKeyDictionary(MutableMapping[_KT, _VT]):
     def __iter__(self) -> Iterator[_KT]: ...
     def copy(self) -> WeakKeyDictionary[_KT, _VT]: ...
     __copy__ = copy
-    def __deepcopy__(self: Self, memo: Any) -> Self: ...
+    def __deepcopy__(self, memo: Any) -> Self: ...
     # These are incompatible with Mapping
     def keys(self) -> Iterator[_KT]: ...  # type: ignore[override]
     def values(self) -> Iterator[_VT]: ...  # type: ignore[override]
@@ -123,9 +123,9 @@ class WeakKeyDictionary(MutableMapping[_KT, _VT]):
         def __ror__(self, other: Mapping[_T1, _T2]) -> WeakKeyDictionary[_KT | _T1, _VT | _T2]: ...
         # WeakKeyDictionary.__ior__ should be kept roughly in line with MutableMapping.update()
         @overload  # type: ignore[misc]
-        def __ior__(self: Self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
+        def __ior__(self, other: SupportsKeysAndGetItem[_KT, _VT]) -> Self: ...
         @overload
-        def __ior__(self: Self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
+        def __ior__(self, other: Iterable[tuple[_KT, _VT]]) -> Self: ...
 
 class finalize:  # TODO: This is a good candidate for to be a `Generic[_P, _T]` class
     def __init__(self, __obj: object, __func: Callable[_P, Any], *args: _P.args, **kwargs: _P.kwargs) -> None: ...
diff --git a/mypy/typeshed/stdlib/webbrowser.pyi b/mypy/typeshed/stdlib/webbrowser.pyi
index d15ae49fd1e8..02edd42e7d59 100644
--- a/mypy/typeshed/stdlib/webbrowser.pyi
+++ b/mypy/typeshed/stdlib/webbrowser.pyi
@@ -65,4 +65,9 @@ if sys.platform == "darwin":
         def open(self, url: str, new: int = 0, autoraise: bool = True) -> bool: ...
 
     class MacOSXOSAScript(BaseBrowser):  # In runtime this class does not have `name` and `basename`
+        if sys.version_info >= (3, 11):
+            def __init__(self, name: str = "default") -> None: ...
+        else:
+            def __init__(self, name: str) -> None: ...
+
         def open(self, url: str, new: int = 0, autoraise: bool = True) -> bool: ...
diff --git a/mypy/typeshed/stdlib/winreg.pyi b/mypy/typeshed/stdlib/winreg.pyi
index 6377492babc7..5b2d09a3bebc 100644
--- a/mypy/typeshed/stdlib/winreg.pyi
+++ b/mypy/typeshed/stdlib/winreg.pyi
@@ -1,8 +1,7 @@
 import sys
-from _typeshed import Self
 from types import TracebackType
 from typing import Any
-from typing_extensions import Literal, TypeAlias, final
+from typing_extensions import Literal, Self, TypeAlias, final
 
 if sys.platform == "win32":
     _KeyType: TypeAlias = HKEYType | int
@@ -93,7 +92,7 @@ if sys.platform == "win32":
     class HKEYType:
         def __bool__(self) -> bool: ...
         def __int__(self) -> int: ...
-        def __enter__(self: Self) -> Self: ...
+        def __enter__(self) -> Self: ...
         def __exit__(
             self, exc_type: type[BaseException] | None, exc_value: BaseException | None, traceback: TracebackType | None
         ) -> bool | None: ...
diff --git a/mypy/typeshed/stdlib/xml/dom/minidom.pyi b/mypy/typeshed/stdlib/xml/dom/minidom.pyi
index d996f66984f9..7bbffb88c8f7 100644
--- a/mypy/typeshed/stdlib/xml/dom/minidom.pyi
+++ b/mypy/typeshed/stdlib/xml/dom/minidom.pyi
@@ -1,7 +1,7 @@
 import sys
 import xml.dom
-from _typeshed import Incomplete, ReadableBuffer, Self, SupportsRead, SupportsWrite
-from typing_extensions import Literal
+from _typeshed import Incomplete, ReadableBuffer, SupportsRead, SupportsWrite
+from typing_extensions import Literal, Self
 from xml.dom.xmlbuilder import DocumentLS, DOMImplementationLS
 from xml.sax.xmlreader import XMLReader
 
@@ -46,7 +46,7 @@ class Node(xml.dom.Node):
     def setUserData(self, key, data, handler): ...
     childNodes: Incomplete
     def unlink(self) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, et, ev, tb) -> None: ...
 
 class DocumentFragment(Node):
@@ -269,7 +269,7 @@ class DOMImplementation(DOMImplementationLS):
     def hasFeature(self, feature: str, version: str | None) -> bool: ...
     def createDocument(self, namespaceURI: str | None, qualifiedName: str | None, doctype: DocumentType | None) -> Document: ...
     def createDocumentType(self, qualifiedName: str | None, publicId: str, systemId: str) -> DocumentType: ...
-    def getInterface(self: Self, feature: str) -> Self | None: ...
+    def getInterface(self, feature: str) -> Self | None: ...
 
 class ElementInfo:
     tagName: Incomplete
diff --git a/mypy/typeshed/stdlib/xml/sax/__init__.pyi b/mypy/typeshed/stdlib/xml/sax/__init__.pyi
index a591258db801..ca981a00d25f 100644
--- a/mypy/typeshed/stdlib/xml/sax/__init__.pyi
+++ b/mypy/typeshed/stdlib/xml/sax/__init__.pyi
@@ -1,5 +1,5 @@
 import sys
-from _typeshed import ReadableBuffer, SupportsRead, _T_co
+from _typeshed import ReadableBuffer, StrPath, SupportsRead, _T_co
 from collections.abc import Iterable
 from typing import Any, NoReturn, Protocol
 from xml.sax.handler import ContentHandler as ContentHandler, ErrorHandler as ErrorHandler
@@ -29,12 +29,19 @@ default_parser_list: list[str]
 
 if sys.version_info >= (3, 8):
     def make_parser(parser_list: Iterable[str] = ...) -> XMLReader: ...
+    def parse(
+        source: StrPath | _SupportsReadClose[bytes] | _SupportsReadClose[str],
+        handler: ContentHandler,
+        errorHandler: ErrorHandler = ...,
+    ) -> None: ...
 
 else:
     def make_parser(parser_list: list[str] = ...) -> XMLReader: ...
+    def parse(
+        source: str | _SupportsReadClose[bytes] | _SupportsReadClose[str],
+        handler: ContentHandler,
+        errorHandler: ErrorHandler = ...,
+    ) -> None: ...
 
-def parse(
-    source: str | _SupportsReadClose[bytes] | _SupportsReadClose[str], handler: ContentHandler, errorHandler: ErrorHandler = ...
-) -> None: ...
 def parseString(string: ReadableBuffer | str, handler: ContentHandler, errorHandler: ErrorHandler | None = ...) -> None: ...
 def _create_parser(parser_name: str) -> XMLReader: ...
diff --git a/mypy/typeshed/stdlib/xmlrpc/client.pyi b/mypy/typeshed/stdlib/xmlrpc/client.pyi
index 536cd6382d0b..7bf701ae716d 100644
--- a/mypy/typeshed/stdlib/xmlrpc/client.pyi
+++ b/mypy/typeshed/stdlib/xmlrpc/client.pyi
@@ -2,13 +2,13 @@ import gzip
 import http.client
 import sys
 import time
-from _typeshed import ReadableBuffer, Self, SupportsRead, SupportsWrite, _BufferWithLen
+from _typeshed import ReadableBuffer, SupportsRead, SupportsWrite, _BufferWithLen
 from collections.abc import Callable, Iterable, Mapping
 from datetime import datetime
 from io import BytesIO
 from types import TracebackType
-from typing import Any, Protocol, Union, overload
-from typing_extensions import Literal, TypeAlias
+from typing import Any, Protocol, overload
+from typing_extensions import Literal, Self, TypeAlias
 
 class _SupportsTimeTuple(Protocol):
     def timetuple(self) -> time.struct_time: ...
@@ -31,7 +31,7 @@ _Marshallable: TypeAlias = (
     | Binary
 )
 _XMLDate: TypeAlias = int | datetime | tuple[int, ...] | time.struct_time
-_HostType: TypeAlias = Union[tuple[str, dict[str, str]], str]
+_HostType: TypeAlias = tuple[str, dict[str, str]] | str
 
 def escape(s: str) -> str: ...  # undocumented
 
@@ -312,7 +312,7 @@ class ServerProxy:
     def __call__(self, attr: Literal["transport"]) -> Transport: ...
     @overload
     def __call__(self, attr: str) -> Callable[[], None] | Transport: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
diff --git a/mypy/typeshed/stdlib/zipfile.pyi b/mypy/typeshed/stdlib/zipfile.pyi
index 0cb6138dfddd..b969d0cf9e6a 100644
--- a/mypy/typeshed/stdlib/zipfile.pyi
+++ b/mypy/typeshed/stdlib/zipfile.pyi
@@ -1,11 +1,11 @@
 import io
 import sys
-from _typeshed import Self, StrOrBytesPath, StrPath, _BufferWithLen
+from _typeshed import StrOrBytesPath, StrPath, _BufferWithLen
 from collections.abc import Callable, Iterable, Iterator
 from os import PathLike
 from types import TracebackType
 from typing import IO, Any, Protocol, overload
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Literal, Self, TypeAlias
 
 __all__ = [
     "BadZipFile",
@@ -150,7 +150,7 @@ class ZipFile:
             compresslevel: int | None = None,
         ) -> None: ...
 
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(
         self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
     ) -> None: ...
@@ -214,12 +214,10 @@ class ZipInfo:
     def __init__(self, filename: str = "NoName", date_time: _DateTuple = ...) -> None: ...
     if sys.version_info >= (3, 8):
         @classmethod
-        def from_file(
-            cls: type[Self], filename: StrPath, arcname: StrPath | None = None, *, strict_timestamps: bool = True
-        ) -> Self: ...
+        def from_file(cls, filename: StrPath, arcname: StrPath | None = None, *, strict_timestamps: bool = True) -> Self: ...
     else:
         @classmethod
-        def from_file(cls: type[Self], filename: StrPath, arcname: StrPath | None = None) -> Self: ...
+        def from_file(cls, filename: StrPath, arcname: StrPath | None = None) -> Self: ...
 
     def is_dir(self) -> bool: ...
     def FileHeader(self, zip64: bool | None = None) -> bytes: ...
diff --git a/mypy/typeshed/stdlib/zoneinfo/__init__.pyi b/mypy/typeshed/stdlib/zoneinfo/__init__.pyi
index 0bdf853f4069..fe994be3e8ff 100644
--- a/mypy/typeshed/stdlib/zoneinfo/__init__.pyi
+++ b/mypy/typeshed/stdlib/zoneinfo/__init__.pyi
@@ -1,7 +1,8 @@
-from _typeshed import Self, StrPath
+from _typeshed import StrPath
 from collections.abc import Iterable, Sequence
 from datetime import datetime, timedelta, tzinfo
 from typing import Any, Protocol
+from typing_extensions import Self
 
 __all__ = ["ZoneInfo", "reset_tzpath", "available_timezones", "TZPATH", "ZoneInfoNotFoundError", "InvalidTZPathWarning"]
 
@@ -14,9 +15,9 @@ class ZoneInfo(tzinfo):
     def key(self) -> str: ...
     def __init__(self, key: str) -> None: ...
     @classmethod
-    def no_cache(cls: type[Self], key: str) -> Self: ...
+    def no_cache(cls, key: str) -> Self: ...
     @classmethod
-    def from_file(cls: type[Self], __fobj: _IOBytes, key: str | None = ...) -> Self: ...
+    def from_file(cls, __fobj: _IOBytes, key: str | None = ...) -> Self: ...
     @classmethod
     def clear_cache(cls, *, only_keys: Iterable[str] | None = ...) -> None: ...
     def tzname(self, __dt: datetime | None) -> str | None: ...