websocket简单使用

摘要：简单实现参考此文章只限于版本大于前期准备端这里会在开始连接时就调用这里会挺住等待发送消息先执行这里在这里停住等待二加密实现这里应该是要填写加密的文件此处没有深入研究三服务器和浏览器的实现此处先执行代码然后再打开浏览器就可以看到过程同步例子

参考:https://websockets.readthedoc...
PS:此文章只限于python版本大于3.6

前期准备

pip install websocket

server端

import asyncio
import websockets

async def hello(websocket, path):
    print(path)                    #这里会在client开始连接时就调用
    name = await websocket.recv()       #这里会挺住,等待client发送消息
    print(f"< {name}")

    greeting = f"Hello {name}!"

    await websocket.send(greeting)
    print(f"> {greeting}")

start_server = websockets.serve(hello, "localhost", 8765)

asyncio.get_event_loop().run_until_complete(start_server)   #先执行这里
asyncio.get_event_loop().run_forever()                      #在这里停住,等待

client

import asyncio
import websockets

async def hello():
    async with websockets.connect(
            "ws://localhost:8765") as websocket:
        name = input("What"s your name? ")

        await websocket.send(name)
        print(f"> {name}")

        greeting = await websocket.recv()
        print(f"< {greeting}")

asyncio.get_event_loop().run_until_complete(hello())  

server

import asyncio
import pathlib
import ssl
import websockets

async def hello(websocket, path):
    name = await websocket.recv()
    print(f"< {name}")

    greeting = f"Hello {name}!"

    await websocket.send(greeting)
    print(f"> {greeting}")

ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
ssl_context.load_cert_chain(
    pathlib.Path(__file__).with_name("localhost.pem"))  #这里应该是要填写加密的文件,此处没有深入研究

start_server = websockets.serve(
    hello, "localhost", 8765, ssl=ssl_context)

asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

client

import asyncio
import pathlib
import ssl
import websockets

ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
ssl_context.load_verify_locations(
    pathlib.Path(__file__).with_name("localhost.pem"))

async def hello():
    async with websockets.connect(
            "wss://localhost:8765", ssl=ssl_context) as websocket:
        name = input("What"s your name? ")

        await websocket.send(name)
        print(f"> {name}")

        greeting = await websocket.recv()
        print(f"< {greeting}")

asyncio.get_event_loop().run_until_complete(hello())

server

import asyncio
import datetime
import random
import websockets

async def time(websocket, path):
    while True:
        now = datetime.datetime.utcnow().isoformat() + "Z"
        await websocket.send(now)
        await asyncio.sleep(random.random() * 3)

start_server = websockets.serve(time, "127.0.0.1", 5678)

asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

browser

PS:此处先执行server代码,然后再打开浏览器就可以看到过程

server

import asyncio
import json
import logging
import websockets

logging.basicConfig()

STATE = {"value": 0}

USERS = set()

def state_event():
    return json.dumps({"type": "state", **STATE})

def users_event():
    return json.dumps({"type": "users", "count": len(USERS)})

async def notify_state():
    if USERS:       # asyncio.wait doesn"t accept an empty list
        message = state_event()
        await asyncio.wait([user.send(message) for user in USERS])

async def notify_users():
    if USERS:       # asyncio.wait doesn"t accept an empty list
        message = users_event()
        await asyncio.wait([user.send(message) for user in USERS])

async def register(websocket):
    USERS.add(websocket)
    await notify_users()

async def unregister(websocket):
    USERS.remove(websocket)
    await notify_users()

async def counter(websocket, path):
    # register(websocket) sends user_event() to websocket
    await register(websocket)
    try:
        await websocket.send(state_event())
        async for message in websocket:
            data = json.loads(message)
            if data["action"] == "minus":
                STATE["value"] -= 1
                await notify_state()
            elif data["action"] == "plus":
                STATE["value"] += 1
                await notify_state()
            else:
                logging.error(
                    "unsupported event: {}", data)
    finally:
        await unregister(websocket)

asyncio.get_event_loop().run_until_complete(
    websockets.serve(counter, "localhost", 6789))
asyncio.get_event_loop().run_forever()

client

    
        
        
    
    
        

            
-
            
?
            
+
        
        

            ? online
        
        
    

websocket提供一个查看当前状态的接口
python -m websockets wss://echo.websocket.org/

如果Python版本是3.5以下

server

import asyncio
import websockets

@asyncio.coroutine
def hello(websocket, path):
    name = yield from websocket.recv()
    print("< {}".format(name))

    greeting = "Hello {}!".format(name)

    yield from websocket.send(greeting)
    print("> {}".format(greeting))

start_server = websockets.serve(hello, "localhost", 8765)

asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

client

import asyncio
import websockets

@asyncio.coroutine
def hello():
    websocket = yield from websockets.connect(
        "ws://localhost:8765/")

    try:
        name = input("What"s your name? ")

        yield from websocket.send(name)
        print("> {}".format(name))

        greeting = yield from websocket.recv()
        print("< {}".format(greeting))

    finally:
        yield from websocket.close()

asyncio.get_event_loop().run_until_complete(hello())