多路复用

服务端
from socket import *
import time
import select
server = socket(AF_INET,SOCK_STREAM)
server.bind(('127.0.0.1',8081))
server.listen(3)
server.setblocking(False)      #accept变为非阻塞状态，
print('server startting...')

reads_l = [server,]  #每次来一个客户端，添加到列表
while True:
    r_l,_,_ = select.select(reads_l,[],[])
    for obj in r_l:   #接收到的对象
        if obj == server:         #server.accept               conn,addr = server.accept
            conn,addr = obj.accept()   #每个对象都有conn，addr
            reads_l.append(conn)
        else:                         #    conn.recv       接收到的数据
            data = obj.recv(1024)    #obj = conn
            obj.send(data.upper())

客户端
from socket import *
client = socket(AF_INET,SOCK_STREAM)
client.connect(('127.0.0.1',8081))
while True:
    msg = input('p;ease:').strip()
    if not msg:continue
    client.send(msg.encode('utf-8'))
    data = client.recv(1024)
    print(data.decode('utf-8'))

　selector模块使用：

#服务端
from socket import *
import selectors

sel=selectors.DefaultSelector()
def accept(server_fileobj,mask):
    conn,addr=server_fileobj.accept()
    sel.register(conn,selectors.EVENT_READ,read)
　　# 将conn，注册到sel中

def read(conn,mask):
    try:
        data=conn.recv(1024)
        if not data:
　　　　　　　# 如果没有数据，删除掉conn
            print('closing',conn)
            sel.unregister(conn)
            conn.close()
            return
        conn.send(data.upper()+b'_SB')
    except Exception:
　　　　　# 如果出现异常，删除掉conn
        print('closing', conn)
        sel.unregister(conn)
        conn.close()



server_fileobj=socket(AF_INET,SOCK_STREAM)
server_fileobj.setsockopt(SOL_SOCKET,SO_REUSEADDR,1)
server_fileobj.bind(('127.0.0.1',8088))
server_fileobj.listen(5)
server_fileobj.setblocking(False) #设置socket的接口为非阻塞
sel.register(server_fileobj,selectors.EVENT_READ,accept) #相当于网select的读列表里append了一个文件句柄server_fileobj,并且绑定了一个回调函数accept

while True:
    events=sel.select() #检测所有的fileobj，是否有完成wait data的
    for sel_obj,mask in events:
        callback=sel_obj.data #callback=accpet
        callback(sel_obj.fileobj,mask) #accpet(server_fileobj,1)

#客户端
from socket import *
c=socket(AF_INET,SOCK_STREAM)
c.connect(('127.0.0.1',8088))

while True:
    msg=input('>>: ')
    if not msg:continue
    c.send(msg.encode('utf-8'))
    data=c.recv(1024)
    print(data.decode('utf-8'))