model.py 文件源码

def __new__(cls, *args, **kwargs):
        instance = super(Model, cls).__new__(cls)

        for field in attr.fields(cls):
            if field.metadata.get('related'):
                target = field.metadata['related']['target']

                setattr(
                    target,
                    cls.__name__.lower() + '_set',
                    RelatedManagerDescriptor(model=cls)
                )

        return cls.objects.add(instance)