Python开发 之 Websocket 的使用示例

1、唠唠叨叨

最近又回顾了下Websocket，发现已经忘的七七八八了。于是用js写了客户端，用python写了服务端，来复习一下这方面的知识。

2、先看一下效果吧

2.1、效果1（一个客户端连上服务的并发送消息）

2.2、效果2（另一个客户端连上服务的并发送消息）

2.3、效果3（服务的收到客户端的全部消息并返回消息）

2.4、效果4（一个客户端掉线并不影响其它socket连接）

2.5、效果5（列取全部连接客户端对象和当前发消息的客户端对象）

3、核心代码

3.1、Python

#! -*- coding: utf-8 -*-
"""
Author: ZhenYuSha
Create Time: 2019-1-14
Info: Websocket 的使用示例
"""
import asyncio
import websockets

websocket_users = set()

# 检测客户端权限，用户名密码通过才能退出循环
async def check_user_permit(websocket):
    print("new websocket_users:", websocket)
    websocket_users.add(websocket)
    print("websocket_users list:", websocket_users)
    while True:
        recv_str = await websocket.recv()
        cred_dict = recv_str.split(":")
        if cred_dict[0] == "admin" and cred_dict[1] == "":
            response_str = "Congratulation, you have connect with server..."
            await websocket.send(response_str)
            print("Password is ok...")
            return True
        else:
            response_str = "Sorry, please input the username or password..."
            print("Password is wrong...")
            await websocket.send(response_str)

# 接收客户端消息并处理，这里只是简单把客户端发来的返回回去
async def recv_user_msg(websocket):
    while True:
        recv_text = await websocket.recv()
        print("recv_text:", websocket.pong, recv_text)
        response_text = f"Server return: {recv_text}"
        print("response_text:", response_text)
        await websocket.send(response_text)

# 服务器端主逻辑
async def run(websocket, path):
    while True:
        try:
            await check_user_permit(websocket)
            await recv_user_msg(websocket)
        except websockets.ConnectionClosed:
            print("ConnectionClosed...", path)    # 链接断开
            print("websocket_users old:", websocket_users)
            websocket_users.remove(websocket)
            print("websocket_users new:", websocket_users)
            break
        except websockets.InvalidState:
            print("InvalidState...")    # 无效状态
            break
        except Exception as e:
            print("Exception:", e)

if __name__ == '__main__':
    print("127.0.0.1:8181 websocket...")
    asyncio.get_event_loop().run_until_complete(websockets.serve(run, "127.0.0.1", 8181))
    asyncio.get_event_loop().run_forever()

3.2、Html（JS）

    <script>
        var socket;
        if ("WebSocket" in window) {
            var ws = new WebSocket("ws://127.0.0.1:8181/test");
            socket = ws;
            ws.onopen = function() {
                console.log('连接成功');
                alert("连接成功, 请输入账号和密码");
            };
            ws.onmessage = function(evt) {
                var received_msg = evt.data;
                document.getElementById("showMes").value+=received_msg+"\n";
            };
            ws.onclose = function() {
                alert("断开了连接");
            };
        } else {
            alert("浏览器不支持WebSocket");
        }
        function sendMeg(){
            var message=document.getElementById("name").value+":"+document.getElementById("mes").value;
            document.getElementById("showMes").value+=message+"\n\n";
            socket.send(message);
        }
    </script>