__init_subclass__ でメタクラスを置きかえる際に使えそうな属性

initsubclass.py

class Piyo:
    pass

# FYI: https://docs.python.jp/3/reference/datamodel.html#object.__init_subclass__
class Philosopher:
    def __init_subclass__(cls, default_name, **kwargs):
        # FYI: https://docs.python.jp/3/library/stdtypes.html#special-attributes
        print(cls.hoge)
        print(cls.__class__)
        print(cls.__class__.__name__)
        print(cls.__name__)
        print(cls.__subclasses__())
        print(cls.__mro__)
        print(object in cls.__mro__)
        print(Piyo in cls.__mro__)
        # Philosopherの定義より後で定義されたクラスは使えない
        # print(Hoge in cls.__mro__)
        super().__init_subclass__(**kwargs)
        cls.default_name = default_name

class AustralianPhilosopher(Philosopher, default_name="Bruce"):
    hoge = 'test'

class Hoge:
    pass