io多路复用（一）

sever端
 1 import socket
 sk1 = socket.socket()
 sk1.bind(('127.0.0.1',8001,))
 sk1.listen()

 sk2 = socket.socket()
 sk2.bind(('127.0.0.1',8002,))
 sk2.listen()

 sk3 = socket.socket()
 sk3.bind(('127.0.0.1',8003,))
 sk3.listen()
 inputs = [sk1,sk2,sk3]
 import select
 while True:
     # [sk1,sk2,sk3]select内部自动监听sk1,sk2,sk3,三个对象，一旦某个句柄发生变化（accept（））
     # 如果有链接sk1
     # r_list = [sk1,sk2]
     r_list,w_list,e_list = select.select(inputs,[],[],1)
     for sk in r_list:
         conn,adress = sk.accept()
         conn.sendall(bytes('hello',encoding='utf-8'))
         conn.close()

客户端，可同时连接多个客户端

 import socket
 obj = socket.socket()
 obj.connect(('127.0.0.1',8001,))

 rec_bytes = obj.recv(1024)
 rec_str = str(rec_bytes,encoding='utf-8')
 print(rec_str)
 obj.close()