Python中的元类编写ORM框架

博客转载：
https://blog.csdn.net/givemefive_y/article/details/79806348
https://blog.csdn.net/eye_water/article/details/78777870
https://www.liaoxuefeng.com/wiki/001374738125095c955c1e6d8bb493182103fac9270762a000/001386820064557c69858840b4c48d2b8411bc2ea9099ba000
https://blog.csdn.net/weixin_40036888/article/details/80343949