python网络编程之UDP面向无连接

面向无连接UDP连接是一种比较方便的连接方式，它不需要和服务器连接，直接将地址和数据封装到一起然后发送，中间如果客户机断开连接，数据也会通过IP地址发送过去。如果IP地址不存在，数据就会消失在网络中。
服务器代码如下：

import socket

HOST = ''
PORT = 8080
ADDRESS = (HOST,PORT)
BUFFER = 1024

client_set = set()

udp_socket = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
udp_socket.bind(ADDRESS)

print("udp server is starting, waiting for data....")
while True:
    msg, addr = udp_socket.recvfrom(BUFFER)
    client_set.add(addr)
    print(addr,"client:",msg.decode('gbk'))

    for client in client_set:
        if client != addr:

            udp_socket.sendto(msg, client)

客户端代码：

import socket

HOST = '192.168.13.21'
PORT = 8080
ADDRESS = (HOST, PORT)
BUFFER = 1024
a = 0

udp_client = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)

info = input("请输入您的昵称：")
udp_client.sendto(info.encode('gbk'),ADDRESS)

while True:
    for i in range(1,a+1):
        msg, addr = udp_client.recvfrom(BUFFER)
        print(addr,"say:",msg.decode('gbk'))
    while True:
        a += 1
        info = input("请输入您要发送的信息：")
        udp_client.sendto(info.encode('gbk'),ADDRESS)
        if info == "BYE":
            break