diff --git a/Lib/typing.py b/Lib/typing.py index 50a8f515945..82107300734 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -2471,8 +2471,9 @@ def final(f): return f -# Some unconstrained type variables. These are used by the container types. -# (These are not for export.) +# Some unconstrained type variables. These were initially used by the container types. +# They were never meant for export and are now unused, but we keep them around to +# avoid breaking compatibility with users who import them. T = TypeVar('T') # Any type. KT = TypeVar('KT') # Key type. VT = TypeVar('VT') # Value type. @@ -2577,8 +2578,6 @@ Type.__doc__ = \ At this point the type checker knows that joe has type BasicUser. """ -# Internal type variable for callables. Not for export. -F = TypeVar("F", bound=Callable[..., Any]) @runtime_checkable class SupportsInt(Protocol): @@ -2631,22 +2630,22 @@ class SupportsIndex(Protocol): @runtime_checkable -class SupportsAbs(Protocol[T_co]): +class SupportsAbs[T](Protocol): """An ABC with one abstract method __abs__ that is covariant in its return type.""" __slots__ = () @abstractmethod - def __abs__(self) -> T_co: + def __abs__(self) -> T: pass @runtime_checkable -class SupportsRound(Protocol[T_co]): +class SupportsRound[T](Protocol): """An ABC with one abstract method __round__ that is covariant in its return type.""" __slots__ = () @abstractmethod - def __round__(self, ndigits: int = 0) -> T_co: + def __round__(self, ndigits: int = 0) -> T: pass @@ -3183,7 +3182,7 @@ re.__name__ = __name__ + '.re' sys.modules[re.__name__] = re -def reveal_type(obj: T, /) -> T: +def reveal_type[T](obj: T, /) -> T: """Reveal the inferred type of a variable. When a static type checker encounters a call to ``reveal_type()``, @@ -3203,6 +3202,11 @@ def reveal_type(obj: T, /) -> T: return obj +class _IdentityCallable(Protocol): + def __call__[T](self, arg: T, /) -> T: + ... + + def dataclass_transform( *, eq_default: bool = True, @@ -3211,7 +3215,7 @@ def dataclass_transform( frozen_default: bool = False, field_specifiers: tuple[type[Any] | Callable[..., Any], ...] = (), **kwargs: Any, -) -> Callable[[T], T]: +) -> _IdentityCallable: """Decorator that marks a function, class, or metaclass as providing dataclass-like behavior. @@ -3288,8 +3292,10 @@ def dataclass_transform( return decorator +type _Func = Callable[..., Any] -def override(method: F, /) -> F: + +def override[F: _Func](method: F, /) -> F: """Indicate that a method is intended to override a method in a base class. Usage: