duplicate-bases / E0241

Message emitted:

Duplicate bases for class %r

Description:

Duplicate use of base classes in derived classes raise TypeErrors.

Problematic code:

class Animal:
    pass


class Cat(Animal, Animal):  # [duplicate-bases]
    pass

Correct code:

class Animal:
    pass


class Bird(Animal):
    pass


class Cat(Animal):
    pass

Created by the classes checker.