python socket 入门

import socket

s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind(("localhost",1234))
s.listen(5)
try:
    while True:
        #accept返回一个元祖,第一个元素cs是新的socket对象，服务器必须通过它与客户通信;第二个元素 address是客户的Internet地址(IP,PORT)。
        cs,addr = s.accept()
        cs.sendall("Welcome to Echo Server")
        while True:
            data = cs.recv(8192)
            if not data: break
            print("recv data: %s" %data)
            cs.sendall(data)
        cs.close()
        print("%s closed at %d" %(addr[0],addr[1]))
finally:
    s.close()