一个最近学习的网站

http://python3-cookbook.readthedocs.io/zh_CN/latest/chapters/p08_classes_and_objects.html

描述器

https://www.jianshu.com/p/58f1df955bda

https://segmentfault.com/a/1190000008994270

http://pyzh.readthedocs.io/en/latest/Descriptor-HOW-TO-Guide.html

__dict__

https://www.jianshu.com/p/cf8450b4b537

经典类和新式类