如何在导入类后修改其行为？

class Pointer:    def __init_subclass__(cls, **kwargs):        bases = tuple(set(cls.__bases__) - {Pointer})        assert len(bases) <= 1, '只能再继承一个类'        assert len(bases), '必须再继承一个类'        bases = bases[0]        for fun_name in dir(cls):            if fun_name not in not_transfer_fun and callable(getattr(cls, fun_name)):                setattr(cls, fun_name, fun_transfer(getattr(cls, fun_name)))        cls.__init__ = __init__        cls.__setattr__ = __setattr__        cls.__getattribute__ = __getattribute__        cls.__value__ = None        cls.__class__ = cls        cls.__type__ = bases        return cls