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Multiple inheritance checks do not consider callable objects as possible subtypes of usual functions #14852
Description
It seems Mypy's method TypeChecker.check_compatibility for checking multiple inheritance compatibility does not consider that callable objects can be subtypes of usual functions, but method TypeChecker.check_method_override_for_base_with_name does so for single inheritance.
For the following example, Mypy reports:
- Definition of "f" in base class "A1" is incompatible with definition in base class "A2" [misc]
- Definition of "f" in base class "A2" is incompatible with definition in base class "A1" [misc]
from typing import Any, Callable, Self
class F:
def __init__(self, f: Callable[[Any, int], int]) -> None:
self.wrapped = f
self.m: Any
def __get__(self, obj: Any, objtype: Any) -> Self:
self.m = obj
return self
def __call__(self, x: int) -> int:
return self.wrapped(self, x)
def dec(f: Callable[[Any, int], int]) -> F:
return F(f)
class A1:
def f(self, x: int) -> int:
return 1 * x
class B1(A1): # no error reported, IMO okay
@dec
def f(self, x: int) -> int:
return 2 * x
class A2:
@dec
def f(self, x: int) -> int:
return 3 * x
class B21(A1, A2): # error reported, IMO okay
pass
class B22(A2, A1): # error reported, IMO not okay
pass
assert B1().f(1) == 2
assert B21().f(1) == 1
assert B22().f(1) == 3
assert hasattr(B1().f, "wrapped")
# assert hasattr(B21().f), "wrapped") # would crash
assert hasattr(B22().f, "wrapped")
Activity
Let the multiple inheritance checks consider callable objects as poss…
Multiple inheritance considers callable objects as subtypes of functi…
Multiple inheritance considers callable objects as subtypes of functi…