WebSocket 和 SocketIO
WebSocket 教程: http://www.ruanyifeng.com/blog/2017/05/websocket.html
WebSocket和SocketIO总结: https://www.cnblogs.com/foupwang/p/7865694.html
使用Flask SocketIO实现WebSocket: https://windrocblog.sinaapp.com/?p=1628
【Flask】 flask-socketio实现WebSocket: https://www.cnblogs.com/franknihao/p/7550043.html