related.py 文件源码

def swappable_setting(self):
        """
        Get the setting that this is powered from for swapping, or None
        if it's not swapped in / marked with swappable=False.
        """
        if self.swappable:
            # Work out string form of "to"
            if isinstance(self.remote_field.model, six.string_types):
                to_string = self.remote_field.model
            else:
                to_string = self.remote_field.model._meta.label
            return apps.get_swappable_settings_name(to_string)
        return None