Use tomllib on Python 3.11 (#12305)

Author: hauntsaninja

mypy-requirements.txt

@@ -1,4 +1,4 @@
 typing_extensions>=3.10
 mypy_extensions>=0.4.3
 typed_ast>=1.4.0,<2; python_version<'3.8'
-tomli>=1.1.0
+tomli>=1.1.0; python_version<'3.11'

mypy/config_parser.py

@@ -6,7 +6,11 @@
 import re
 import sys
 
-import tomli
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    import tomli as tomllib
+
 from typing import (Any, Callable, Dict, List, Mapping, MutableMapping,  Optional, Sequence,
                     TextIO, Tuple, Union)
 from typing_extensions import Final, TypeAlias as _TypeAlias
@@ -178,8 +182,8 @@ def parse_config_file(options: Options, set_strict_flags: Callable[[], None],
             continue
         try:
             if is_toml(config_file):
-                with open(config_file, encoding="utf-8") as f:
-                    toml_data = tomli.loads(f.read())
+                with open(config_file, "rb") as f:
+                    toml_data = tomllib.load(f)
                 # Filter down to just mypy relevant toml keys
                 toml_data = toml_data.get('tool', {})
                 if 'mypy' not in toml_data:
@@ -191,7 +195,7 @@ def parse_config_file(options: Options, set_strict_flags: Callable[[], None],
                 config_parser.read(config_file)
                 parser = config_parser
                 config_types = ini_config_types
-        except (tomli.TOMLDecodeError, configparser.Error, ConfigTOMLValueError) as err:
+        except (tomllib.TOMLDecodeError, configparser.Error, ConfigTOMLValueError) as err:
             print("%s: %s" % (config_file, err), file=stderr)
         else:
             if config_file in defaults.SHARED_CONFIG_FILES and 'mypy' not in parser:

mypy/modulefinder.py

@@ -12,6 +12,11 @@
 import sys
 from enum import Enum, unique
 
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    import tomli as tomllib
+
 from typing import Dict, Iterator, List, NamedTuple, Optional, Set, Tuple, Union
 from typing_extensions import Final, TypeAlias as _TypeAlias
 
@@ -449,10 +454,8 @@ def _is_compatible_stub_package(self, stub_dir: str) -> bool:
         """
         metadata_fnam = os.path.join(stub_dir, 'METADATA.toml')
         if os.path.isfile(metadata_fnam):
-            # Delay import for a possible minor performance win.
-            import tomli
-            with open(metadata_fnam, encoding="utf-8") as f:
-                metadata = tomli.loads(f.read())
+            with open(metadata_fnam, "rb") as f:
+                metadata = tomllib.load(f)
             if self.python_major_ver == 2:
                 return bool(metadata.get('python2', False))
             else:

setup.py

@@ -198,7 +198,7 @@ def run(self):
       install_requires=["typed_ast >= 1.4.0, < 2; python_version<'3.8'",
                         'typing_extensions>=3.10',
                         'mypy_extensions >= 0.4.3',
-                        'tomli>=1.1.0',
+                        "tomli>=1.1.0; python_version<'3.11'",
                         ],
       # Same here.
       extras_require={