https://tool.lu/markdown https://blog.csdn.net/weixin_43784462/article/details/88718798
https://www.cnblogs.com/0zcl/p/6022774.html https://www.cnblogs.com/ywxbbbbb/p/9980722.html
python 【socket】
原文：https://www.cnblogs.com/amize/p/15196058.html
