老师博客：http://www.cnblogs.com/Eva-J/articles/8244551.html#_label4
基于udp的简单的聊天代码
说明：这段代码，显示有client向servre发送消息，然后有server在向client发送消息，简单的模拟聊天，如果有一方的聊天信息是bye的话，便会终止聊天对话，最好对方另外一方也可以同时说bye，才能结束双方的聊天信息。
server端
import socket
server=socket.socket(type=socket.SOCK_DGRAM)
ip_port=('192.168.43.155',8893)
server.bind(ip_port)
while 1:
message,address=server.recvfrom(1024)
print('来自',address,':',message.decode('utf-8'),)
server_say=input('what are you want say:').encode('utf-8')
server.sendto(server_say,address)
if 'bye' in message.decode('utf-8'):
break
server.close()
client端
import socket
client=socket.socket(type=socket.SOCK_DGRAM)
ip_port=('192.168.43.155',8893)
while 1:
client_say=input('what are you want to say?:').encode('utf-8')
client.sendto(client_say,ip_port)
message,address=client.recvfrom(1024)
ret = message.decode('utf-8')
print('来自',address,'的消息：',ret)
if ret=='bye':
break
client.close()