invalid-class-object / E0243

Message emitted:

Invalid assignment to '__class__'. Should be a class definition but got a '%s'

Description:

Used when an invalid object is assigned to a __class__ property. Only a class is permitted.

Problematic code:

class Apple:
    pass


Apple.__class__ = 1  # [invalid-class-object]

Correct code:

class Apple:
    pass


class RedDelicious:
    pass


Apple.__class__ = RedDelicious

Created by the classes checker.