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Would it be possible to broaden classmethod to accept ParamSpec when MyPy's support is better? #7689
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This is on my to-do list for as soon as mypy 0.950 is released 🙂
Reacted by Neil GirdharThough I'm not sure how much of a difference this will make, considering how thoroughly type checkers special case classmethod (and staticmethod).
Reacted by Alex Waygood and Neil GirdharAlso,
staticmethodis quite a lot easier thanclassmethod.staticmethoddoesn't change the signature of the function it wraps, butclassmethoddoes -- it requiresConcatenate. It would be something like this:import sys from typing import TypeVar, Callable, Generic from typing_extensions import ParamSpec, Concatenate _P = ParamSpec("_P") _R_co = TypeVar("_R_co", covariant=True) _T = TypeVar("_T") class classmethod(Generic[_P, _R_co, _T]): @property def __func__(self) -> Callable[Concatenate[_T, _P], _R_co]: ... @property def __isabstractmethod__(self) -> bool: ... def __init__(self: classmethod[_P, _R_co, _T], __f: Callable[Concatenate[_T, _P], _R_co]) -> None: ... def __get__(self, __obj: _T | None, __type: type[_T] | None = ...) -> Callable[_P, _R_co]: ... if sys.version_info >= (3, 10): __name__: str __qualname__: str @property def __wrapped__(self) -> Callable[Concatenate[_T, _P], _R_co]: ...
Reacted by Neil Girdhar@JelleZijlstra Yup, I just learned about that here. It's not too big a deal since it's very rare that you decorate class methods, but maybe after
classmethodis broadened they might consider producing aclassmethod[P, R, T]instead of aCallable[Concatenate[type[T], P], R].Reacted by Jelle Zijlstra and Alex WaygoodMypy 0.950 is now out, but sadly we still cannot use
ParamSpecinclassmethodorstaticmethoddue to python/mypy#12011. (abc.abstractclassmethodandabc.abstractstaticmethodinherit fromclassmethodandstaticmethodrespectively, so while that mypy issue is outstanding, we cannot makebuiltins.staticmethodorbuiltins.classmethodgeneric over a parameter specification without breaking those two classes.)Reacted by Neil Girdhar
It could be something like: