Method resolution order with diamond inheritance

gistfile1.py

"""
Method resolution order with diamond inheritance
>>> print(Class3.mro())
[Class3, Class1_2, Class1_1, Class2, Class0, <class 'object'>]
"""
class Meta(type):
    def __repr__(self):
        return self.__name__
class Class0(metaclass=Meta):
    pass
class Class1_1(Class0):
    pass
class Class1_2(Class1_1):
    pass
class Class2(Class0):
    pass
class Class3(Class1_2, Class2):
    pass

if __name__=="__main__":
    import doctest
    doctest.testmod()