https://cs.pynote.net/sf/python/
https://amontalenti.com/python-training
https://www.w3cschool.cn/python3/python3-thz7323h.html
https://docs.python.org/zh-cn/3.7/tutorial/
https://www.liaoxuefeng.com/wiki/1016959663602400/
https://python3-cookbook.readthedocs.io/zh_CN/latest/preface.html
http://c.biancheng.net/view/4599.html
