------类似于cmd的功能，client执行命令，server发命令结果发送到client

-----------server.py-------------------

import subprocess
#subprocess.Popen,主要用Popen这个类实现shell

import socket
sk=socket.socket()
print(sk)
address=('127.0.0.1',8003)
sk.bind(address)
sk.listen(3)
print('waiting.....')
while True:
    conn,addr = sk.accept()
    print(addr)
    while True:
        try:
            data = conn.recv(1024)
        except Exception:
            break
        if not data: break
        print('.....', str(data, 'utf8'))
obj=subprocess.Popen(str(data,'utf8'),shell=True,stdout=subprocess.PIPE)
        #stdout=subprocess.PIPE表示通过管道PIP由你的子进程转到我主进程并封装到obj对象里
　　　　　----即这一行和下面这一行的功能就是把client发来指令的结果解出来

        cmd_result=obj.stdout.read()
        result_len=bytes(str(len(cmd_result)),'utf8')   #算出它的大小
        conn.sendall(result_len)      #把这个大小的数字传给client

        conn.recv(1024)

        conn.sendall(bytes(cmd_result))
sk.close()


-----------------------------client.py-------------------------------

import socket
sk=socket.socket()
print(sk)
address=('127.0.0.1',8003)
sk.connect(address)
while True:
    inp=input('>>>')
    if inp == 'exit':
        break
    sk.send(bytes(inp,'utf8'))

    result_len=int(str(sk.recv(1024),'utf8'))

    sk.sendall(bytes('111','utf8'))

    print(result_len)
    data=bytes()
    while len(data) != result_len:
        recv= sk.recv(1024)
        data+=recv

    print(str(data,'gbk'))
sk.close()

结果如下图：在client执行dir和ipconfig等命令能拿到结果