1、安装gevent-websocket

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple/ gevent-websocket

2、chat.py文件内容如下：

from flask import Flask,request,render_template
import json
from geventwebsocket.handler import WebSocketHandler
from gevent.pywsgi import WSGIServer
from geventwebsocket.websocket import WebSocket

user_dict = {}

chat_app = Flask(__name__)
@chat_app.route('/ws/<username>')
def ws_chat(username):
    user_socket = request.environ.get('wsgi.websocket') # type:WebSocket
    user_dict[username]=user_socket
    while 1:
        msg = user_socket.receive()  # 等待接收客户端发来的数据
        msg_dict = json.loads(msg)
        msg_dict['from_user'] = username
        to_user = msg_dict.get('to_user')
        if to_user == "":  # 如果用户名是空表示群发
            for uname, uwebsocket in user_dict.items():
                if uname == username:  # 群发时不用给自己发
                    continue
                uwebsocket.send(json.dumps(msg_dict))
            continue
        to_user_socket = user_dict.get(to_user)
        if not to_user_socket:  # 判断用户字典中是否存在用户的websocket连接
            continue
        try:
            msg_dict['from_user'] = msg_dict['from_user'] + '@私聊我'
            to_user_socket.send(json.dumps(msg_dict))
        except:
            user_dict.pop(to_user)

@chat_app.route('/webchat')
def webchat():
    return render_template('public_chat.html')

if __name__ == '__main__':
    server = WSGIServer(('0.0.0.0',9527),chat_app,handler_class=WebSocketHandler)
    server.serve_forever()

3、web_chat.html文件部分内容如下：

<p>你的名字：<input type="text" id="username">
    <button onclick="open_ws()">登陆聊天室</button>
</p>
<form onsubmit="return false;">
    <h3>WebSocket 聊天室：</h3>
    <textarea id="responseText" style="width: 500px; height: 300px;"></textarea>
    <br>
    给：<input type="text" id="to_user">消息内容：<input type="text" id="message">
    <input type="button" value="发送消息" onclick="send_msg()">
    <input type="button" onclick="javascript:document.getElementById('responseText').value=''"
           value="清空聊天记录">
</form>

4、js代码如下：

<script type="application/javascript">
    var ws = null;
    function open_ws() {
        var username = document.getElementById('username').value;
        ws = new WebSocket("ws://192.168.16.239:9527/ws/" + username);
        ws.onopen = function () {
            alert("登陆成功");
        };

        ws.onmessage = function (eventMessage) {
            // 显示消息记录
            var chat = JSON.parse(eventMessage.data);
            console.log(chat);
            var chat_content = document.getElementById('responseText');
            chat_content.value = chat_content.value + "\n" + chat.from_user + " : " + chat.chat;
        };
    }

    function send_msg() {
        // 发送消息
        var to_user = document.getElementById("to_user").value;
        var msg = document.getElementById("message").value;
        var send_str = {
            to_user: to_user,
            chat: msg
        };
        ws.send(JSON.stringify(send_str));
        var chat_content = document.getElementById("responseText");
        chat_content.value = chat_content.value + "\n" + "我： " + msg;
    }
</script>

最终的效果图如下：