tcp协议（三次握手 四次挥手）

server端

import socket
sk=socket.socket()
sk.bind(('127.0.0.1',9001))
sk.listen()
while 1:
    conn,addr=sk.accept()
    while 1:
        send_msg=input('>>>').strip()
        conn.send(send_msg.encode('utf-8'))
        if send_msg.upper()=='Q':
            break
        recv_msg=conn.recv(1024).decode('utf-8')
        if recv_msg.upper()=='Q':
            break
        print(recv_msg)
    print('over')
    conn.close()

sk.close()

client 端

import socket
sk=socket.socket()
sk.connect(('127.0.0.1',9001))

while 1:
    recv_msg=sk.recv(1024).decode('utf-8')
    if recv_msg.upper()=='Q':
        break
    print(recv_msg)
    send_msg=input('>>>').strip()
    sk.send(send_msg.encode('utf-8'))
    if send_msg.upper()=='Q':
        break
print('over')
sk.close()