python类add_to_class()的实例源码

def __init__(self, *args, **kwargs):
        super(RevisionModelMixin, self).__init__(*args, **kwargs)
        # register the get method for related_name on the user model
        related_name_user = getattr(self._meta, 'related_name_user', '')

        if related_name_user != '':
            User.add_to_class("get_" + related_name_user,
                              lambda user: # user will be set by the calling object afterwards
                              get_all_objects_created_by_user(user=user,
                                                              object_type=ContentType.objects.get_for_model(self)))