invalid-metaclass / E1139

Message emitted:

Invalid metaclass %r used

Description:

Emitted whenever we can detect that a class is using, as a metaclass, something which might be invalid for using as a metaclass.

Problematic code:

class Apple(metaclass=int):  # [invalid-metaclass]
    pass

Correct code:

class Plant:
    pass


class Apple(Plant):
    pass

Created by the typecheck checker.