import pickle   # python pickle module
import _pickle  # c pickle module


class A:
    __slots__ = 'my_attribute'

    def __init__(self, value):
        self.my_attribute = value

    # a class with slots must define a __getstate__ method
    def __getstate__(self):
        return None, {'my_attribute': self.my_attribute}


class B:
    __slots__ = 'my_attribute'

    def __init__(self, value):
        self.my_attribute = value

    # a class with slots must define a __getstate__ method
    def __getstate__(self):
        return {}, {'my_attribute': self.my_attribute}


if __name__ == "__main__":
    for cls in [A, B]:

        print('trying to depickle {}'.format(cls))
        obj = cls(10)

        # pickle_depickle using the pythonic pickle
        depickled_obj = pickle._loads(pickle._dumps(obj))
        assert isinstance(depickled_obj, cls)
        assert depickled_obj.my_attribute == 10

        # pickle_depickle using the c pickle
        c_depickled_obj = _pickle.loads(_pickle.dumps(obj))
        assert isinstance(c_depickled_obj, cls)
        assert depickled_obj.my_attribute == 10