python socketio客户端与服务端连接方式

1.socketio和websocket 的区别

WebSocket是一种通信协议，它通过TCP连接在客户端和服务器之间提供双向通信，WebSocket连接始终保持打开状态，因此它们允许实时数据传输。当客户端向服务器触发请求时，它不会在接收到响应时关闭连接，而是会持续存在并等待客户端或服务器终止请求。

本文章介绍flask socketio 和tornado websocket使用例子 

Socket.IO 是一个库，可用于在客户端和Web服务器之间进行实时和全双工通信。它使用WebSocket协议提供接口。通常，它分为两部分，WebSocket和Socket.io都是事件驱动的库.

简单说 socketio 是对websocket的封装 服务端用socketio客户端也要用socketio 服务端用websocket客户端也要用websocket

SocketIO时，不用担心兼容问题，底层会自动选用最佳的通信方式。因此说，WebSocket是SocketIO的一个子集。

broadcast 为True 进行全员广播

ws.emit('user_message', {"test_111": random.randint(1, 10), "ut": ut}, broadcast=True)

所需要的安装包

python-engineio==3.13.1
python-socketio==4.6.0
Flask-SocketIO==4.3.1
Werkzeug==1.0.1
flask==1.0.2

客户端连接方式

import socketio

sio = socketio.Client()
ut = "1"


@sio.event
def connect():
    print('connection established')


# 监听服务端推送消息
@sio.event
def user_message(data):
    print('user_message received with ', data)
    # sio.emit('my response', {'response': 'my response'})


@sio.event
def disconnect():
    print('disconnected from server')


# 连接服务端 IP+端口
sio.connect('http://localhost:8091')
print("000")

# 向服务端发送消息
sio.emit('sub_user_message', ut)
sio.wait()

服务端起socketio方式

# -*- coding: utf8 -*-

# socketio要想与flask通信必须打补丁

from gevent import monkey

monkey.patch_all()
print('monkey.patch_all()')

from flask import Flask
from werkzeug.utils import import_string
from flask_socketio import SocketIO
import flask_socketio as ws
import time

webapp = Flask(__name__, static_url_path='/static')
webapp.config.from_object("config.Default")  # 引入配置文件config.py 下Default 对象

try:
    local_cfg = import_string('local_cfg.Config')
    webapp.config.from_object(local_cfg)
except:
    pass
webapp.debug = webapp.config.get("DEBUG", False)
webapp.testing = webapp.config.get("TESTING", False)
webapp.static_folder = webapp.config.get('STATIC_BASE', 'static')
webapp.template_folder = webapp.config.get('TEMPLATE_BASE', './templates')

REDIS_HOST = '127.0.0.1'
REDIS_PORT = 6379
REDIS_DB = 10

SOCKETIO_MESSAGE_QUEUE = 'redis://:@%s:%d/%d' % (
    REDIS_HOST, REDIS_PORT, REDIS_DB)  # 通过redis 实现socketio 与flask 进行通信 必须要打补丁
# 无论是否是在WSAPP的环境中，
# 都需要初始化socket_io，
# 因为WEBAPP需要通过它和WSAPP进行通信

socket_io = SocketIO(webapp, cors_allowed_origins='*', message_queue=SOCKETIO_MESSAGE_QUEUE)


@socket_io.on('connect')
def msg_connect():
    print("111111 connect")
    ws.emit('msg_connect', {'data': 'Connected'})

    ut = "1"
    if ut:
        ws.join_room('wx_scan_login.' + ut)


@socket_io.on('sub_user_message')
def sub_user_message(*args, **kwargs):
    """
    用户需要登录访问加到user_message 房间判断用户登录
    :return:
    """
    print(*args)

    print("sub_user_message")
    ut = str(args)

    if ut:
        # 加入房间 房间名称 user_message.
        # 服务端对用户按要求加入不同房间 一个用户一个房间或多个用户一个房间
        ws.join_room('user_message.' + ut)
    while True:
        # 客户端向服务端推送消息 事件名称为:user_message 客户端要监听此事件
        ws.emit('user_message',
                {'data': {'status': 0, 'msg': '支付失败'}, 'command': 'pay'},
                room='user_message.' + ut)
        time.sleep(1)
        import random
        if ut == "12345":  # broadcast为True，进行全员广播,调用一次全员广播一次
            ws.emit('user_message', {"test_111": random.randint(1, 10), "ut": ut}, broadcast=True)


@socket_io.on('disconnect')
def msg_disconnect():
    print('Client disconnected')


socket_io.run(webapp, host='127.0.0.1', port=8091)

获取断开用户的id 可以flask 上下文设置

Tornado websocket

server 

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import logging
import tornado.web
import tornado.websocket
import tornado.ioloop
import tornado.options

from tornado.options import define, options

define("port", default=3000, help="run on the given port", type=int)


class Application(tornado.web.Application):
    def __init__(self):
        handlers = [(r"/", MainHandler)]
        settings = dict(debug=True)
        tornado.web.Application.__init__(self, handlers, **settings)


class MainHandler(tornado.websocket.WebSocketHandler):
    def check_origin(self, origin):
        return True

    def open(self):
        logging.info("A client connected.")

    def on_close(self):
        logging.info("A client disconnected")

    def on_message(self, message):
        logging.info("message: {}".format(message))


def main():
    tornado.options.parse_command_line()
    app = Application()
    app.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()


if __name__ == "__main__":
    main()

client

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from tornado.ioloop import IOLoop, PeriodicCallback
from tornado import gen
from tornado.websocket import websocket_connect


class Client(object):
    def __init__(self, url, timeout):
        self.url = url
        self.timeout = timeout
        self.ioloop = IOLoop.instance()
        self.ws = None
        self.connect()
        PeriodicCallback(self.keep_alive, 20000).start()
        self.ioloop.start()

    @gen.coroutine
    def connect(self):
        print "trying to connect"
        try:
            self.ws = yield websocket_connect(self.url)
            print ""
        except Exception, e:
            print "connection error"
        else:
            print "connected"
            self.run()

    @gen.coroutine
    def run(self):
        while True:
            msg = yield self.ws.read_message()
            print "msg:",msg
            if msg is None:
                print "connection closed"
                self.ws = None
                break

    def keep_alive(self):
        if self.ws is None:
            self.connect()
        else:
            self.ws.write_message("keep alive")

if __name__ == "__main__":
    client = Client("ws://localhost:8061/notify/anonymous?ut=RRYhwCzTbAi3945zsNjv", 5)