diamond.py

class Superclass:

    def class_names(self):
        return 'I am super class'


class ClassA(Superclass):

    def class_names(self):
        return 'I am class A'


class ClassB(Superclass):

    def class_names(self):
        return 'I am class B'


class ClassC(ClassA, ClassB):

    def class_names(self):
        return 'I am class C'


obj_c = ClassC()

print(obj_c.class_names())