narrow signature of __contains__ for str-like classes (#2967)

Fixes #2937

Author: JelleZijlstra

stdlib/2/__builtin__.pyi

@@ -385,7 +385,8 @@ else:
         def __ge__(self, x: unicode) -> bool: ...
 
         def __len__(self) -> int: ...
-        def __contains__(self, s: object) -> bool: ...
+        # The argument type is incompatible with Sequence
+        def __contains__(self, s: Union[unicode, bytes]) -> bool: ...  # type: ignore
         def __iter__(self) -> Iterator[unicode]: ...
         def __str__(self) -> str: ...
         def __repr__(self) -> str: ...
@@ -520,7 +521,8 @@ class str(Sequence[str], _str_base):
         def __add__(self, s: str) -> str: ...
     else:
         def __add__(self, s: AnyStr) -> AnyStr: ...
-    def __contains__(self, o: object) -> bool: ...
+    # Incompatible with Sequence.__contains__
+    def __contains__(self, o: Union[str, Text]) -> bool: ...  # type: ignore
     def __eq__(self, x: object) -> bool: ...
     def __ge__(self, x: Text) -> bool: ...
     def __getitem__(self, i: Union[int, slice]) -> str: ...
@@ -622,7 +624,8 @@ if sys.version_info >= (3,):
         def __rmul__(self, n: int) -> bytes: ...
         if sys.version_info >= (3, 5):
             def __mod__(self, value: Any) -> bytes: ...
-        def __contains__(self, o: object) -> bool: ...
+        # Incompatible with Sequence.__contains__
+        def __contains__(self, o: Union[int, bytes]) -> bool: ...  # type: ignore
         def __eq__(self, x: object) -> bool: ...
         def __ne__(self, x: object) -> bool: ...
         def __lt__(self, x: bytes) -> bool: ...
@@ -754,7 +757,8 @@ class bytearray(MutableSequence[int], ByteString):
         def __imul__(self, n: int) -> bytearray: ...
     if sys.version_info >= (3, 5):
         def __mod__(self, value: Any) -> bytes: ...
-    def __contains__(self, o: object) -> bool: ...
+    # Incompatible with Sequence.__contains__
+    def __contains__(self, o: Union[int, bytes]) -> bool: ...  # type: ignore
     def __eq__(self, x: object) -> bool: ...
     def __ne__(self, x: object) -> bool: ...
     def __lt__(self, x: bytes) -> bool: ...

stdlib/2and3/builtins.pyi

@@ -385,7 +385,8 @@ else:
         def __ge__(self, x: unicode) -> bool: ...
 
         def __len__(self) -> int: ...
-        def __contains__(self, s: object) -> bool: ...
+        # The argument type is incompatible with Sequence
+        def __contains__(self, s: Union[unicode, bytes]) -> bool: ...  # type: ignore
         def __iter__(self) -> Iterator[unicode]: ...
         def __str__(self) -> str: ...
         def __repr__(self) -> str: ...
@@ -520,7 +521,8 @@ class str(Sequence[str], _str_base):
         def __add__(self, s: str) -> str: ...
     else:
         def __add__(self, s: AnyStr) -> AnyStr: ...
-    def __contains__(self, o: object) -> bool: ...
+    # Incompatible with Sequence.__contains__
+    def __contains__(self, o: Union[str, Text]) -> bool: ...  # type: ignore
     def __eq__(self, x: object) -> bool: ...
     def __ge__(self, x: Text) -> bool: ...
     def __getitem__(self, i: Union[int, slice]) -> str: ...
@@ -622,7 +624,8 @@ if sys.version_info >= (3,):
         def __rmul__(self, n: int) -> bytes: ...
         if sys.version_info >= (3, 5):
             def __mod__(self, value: Any) -> bytes: ...
-        def __contains__(self, o: object) -> bool: ...
+        # Incompatible with Sequence.__contains__
+        def __contains__(self, o: Union[int, bytes]) -> bool: ...  # type: ignore
         def __eq__(self, x: object) -> bool: ...
         def __ne__(self, x: object) -> bool: ...
         def __lt__(self, x: bytes) -> bool: ...
@@ -754,7 +757,8 @@ class bytearray(MutableSequence[int], ByteString):
         def __imul__(self, n: int) -> bytearray: ...
     if sys.version_info >= (3, 5):
         def __mod__(self, value: Any) -> bytes: ...
-    def __contains__(self, o: object) -> bool: ...
+    # Incompatible with Sequence.__contains__
+    def __contains__(self, o: Union[int, bytes]) -> bool: ...  # type: ignore
     def __eq__(self, x: object) -> bool: ...
     def __ne__(self, x: object) -> bool: ...
     def __lt__(self, x: bytes) -> bool: ...