Remove some pytype workarounds from stdlib

python · AlexWaygood · Jul 27, 2025 · Jul 27, 2025 · Jul 27, 2025 · Jul 27, 2025
commit a3c08952b0aa51327b54bb33b0efbd2d284b60a2
diff --git a/stdlib/asyncio/base_futures.pyi b/stdlib/asyncio/base_futures.pyi
@@ -1,19 +1,17 @@
+from _asyncio import Future
 from collections.abc import Callable, Sequence
 from contextvars import Context
 from typing import Any, Final
+from typing_extensions import TypeIs
 
 from . import futures
 
 __all__ = ()
 
-# asyncio defines 'isfuture()' in base_futures.py and re-imports it in futures.py
-# but it leads to circular import error in pytype tool.
-# That's why the import order is reversed.
-from .futures import isfuture as isfuture
-
 _PENDING: Final = "PENDING"  # undocumented
 _CANCELLED: Final = "CANCELLED"  # undocumented
 _FINISHED: Final = "FINISHED"  # undocumented
 
+def isfuture(obj: object) -> TypeIs[Future[Any]]: ...
 def _format_callbacks(cb: Sequence[tuple[Callable[[futures.Future[Any]], None], Context]]) -> str: ...  # undocumented
 def _future_repr_info(future: futures.Future[Any]) -> list[str]: ...  # undocumented
diff --git a/stdlib/asyncio/futures.pyi b/stdlib/asyncio/futures.pyi
@@ -1,9 +1,9 @@
 import sys
 from _asyncio import Future as Future
 from concurrent.futures._base import Future as _ConcurrentFuture
-from typing import Any, TypeVar
-from typing_extensions import TypeIs
+from typing import TypeVar
 
+from .base_futures import isfuture as isfuture
 from .events import AbstractEventLoop
 
 # Keep asyncio.__all__ updated with any changes to __all__ here
@@ -16,8 +16,4 @@ else:
 
 _T = TypeVar("_T")
 
-# asyncio defines 'isfuture()' in base_futures.py and re-imports it in futures.py
-# but it leads to circular import error in pytype tool.
-# That's why the import order is reversed.
-def isfuture(obj: object) -> TypeIs[Future[Any]]: ...
 def wrap_future(future: _ConcurrentFuture[_T] | Future[_T], *, loop: AbstractEventLoop | None = None) -> Future[_T]: ...
diff --git a/stdlib/builtins.pyi b/stdlib/builtins.pyi
@@ -1526,7 +1526,6 @@ def iter(object: Callable[[], _T | None], sentinel: None, /) -> Iterator[_T]: ..
 @overload
 def iter(object: Callable[[], _T], sentinel: object, /) -> Iterator[_T]: ...
 
-# Keep this alias in sync with unittest.case._ClassInfo
 if sys.version_info >= (3, 10):
     _ClassInfo: TypeAlias = type | types.UnionType | tuple[_ClassInfo, ...]
 else:

diff --git a/stdlib/optparse.pyi b/stdlib/optparse.pyi
@@ -24,8 +24,7 @@ __all__ = [
     "BadOptionError",
     "check_choice",
 ]
-# pytype is not happy with `NO_DEFAULT: Final = ("NO", "DEFAULT")`
-NO_DEFAULT: Final[tuple[Literal["NO"], Literal["DEFAULT"]]]
+NO_DEFAULT: Final = ("NO", "DEFAULT")
 SUPPRESS_HELP: Final = "SUPPRESSHELP"
 SUPPRESS_USAGE: Final = "SUPPRESSUSAGE"
 

diff --git a/stdlib/re.pyi b/stdlib/re.pyi
@@ -239,9 +239,7 @@ if sys.version_info < (3, 13):
     T: Final = RegexFlag.T
     TEMPLATE: Final = RegexFlag.TEMPLATE
 if sys.version_info >= (3, 11):
-    # pytype chokes on `NOFLAG: Final = RegexFlag.NOFLAG` with `LiteralValueError`
-    # mypy chokes on `NOFLAG: Final[Literal[RegexFlag.NOFLAG]]` with `Literal[...] is invalid`
-    NOFLAG = RegexFlag.NOFLAG
+    NOFLAG: Final = RegexFlag.NOFLAG
 _FlagsType: TypeAlias = int | RegexFlag
 
 # Type-wise the compile() overloads are unnecessary, they could also be modeled using

diff --git a/stdlib/typing_extensions.pyi b/stdlib/typing_extensions.pyi
@@ -59,6 +59,8 @@ from typing import (  # noqa: Y022,Y037,Y038,Y039,UP035
     TypeVar as _TypeVar,
     Union as Union,
     _Alias,
+    _Final as _Final,
+    _SpecialForm as _SpecialForm,
     cast as cast,
     no_type_check as no_type_check,
     no_type_check_decorator as no_type_check_decorator,
@@ -204,15 +206,6 @@ _TC = _TypeVar("_TC", bound=type[object])
 _T_co = _TypeVar("_T_co", covariant=True)  # Any type covariant containers.
 _T_contra = _TypeVar("_T_contra", contravariant=True)
 
-class _Final: ...  # This should be imported from typing but that breaks pytype
-
-# unfortunately we have to duplicate this class definition from typing.pyi or we break pytype
-class _SpecialForm(_Final):
-    def __getitem__(self, parameters: Any) -> object: ...
-    if sys.version_info >= (3, 10):
-        def __or__(self, other: Any) -> _SpecialForm: ...
-        def __ror__(self, other: Any) -> _SpecialForm: ...
-
 # Do not import (and re-export) Protocol or runtime_checkable from
 # typing module because type checkers need to be able to distinguish
 # typing.Protocol and typing_extensions.Protocol so they can properly

diff --git a/stdlib/unittest/case.pyi b/stdlib/unittest/case.pyi
@@ -2,18 +2,16 @@ import logging
 import sys
 import unittest.result
 from _typeshed import SupportsDunderGE, SupportsDunderGT, SupportsDunderLE, SupportsDunderLT, SupportsRSub, SupportsSub
+from builtins import _ClassInfo
 from collections.abc import Callable, Container, Iterable, Mapping, Sequence, Set as AbstractSet
 from contextlib import AbstractContextManager
 from re import Pattern
 from types import GenericAlias, TracebackType
 from typing import Any, AnyStr, Final, Generic, NoReturn, Protocol, SupportsAbs, SupportsRound, TypeVar, overload
-from typing_extensions import Never, ParamSpec, Self, TypeAlias
+from typing_extensions import Never, ParamSpec, Self
 from unittest._log import _AssertLogsContext, _LoggingWatcher
 from warnings import WarningMessage
 
-if sys.version_info >= (3, 10):
-    from types import UnionType
-
 _T = TypeVar("_T")
 _S = TypeVar("_S", bound=SupportsSub[Any, Any])
 _E = TypeVar("_E", bound=BaseException)
@@ -60,14 +58,6 @@ class SkipTest(Exception):
 
 class _SupportsAbsAndDunderGE(SupportsDunderGE[Any], SupportsAbs[Any], Protocol): ...
 
-# Keep this alias in sync with builtins._ClassInfo
-# We can't import it from builtins or pytype crashes,
-# due to the fact that pytype uses a custom builtins stub rather than typeshed's builtins stub
-if sys.version_info >= (3, 10):
-    _ClassInfo: TypeAlias = type | UnionType | tuple[_ClassInfo, ...]
-else:
-    _ClassInfo: TypeAlias = type | tuple[_ClassInfo, ...]
-
 class TestCase:
     failureException: type[BaseException]
     longMessage: bool