# -*-coding：utf-8 -*-
# BY WANGCC
import socket

phone=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
phone.connect(('127.0.0.1',9901))
while True:
    #1、发命令
    cmd=input('>>: ').strip() #ls /etc
    if not cmd:continue
    phone.send(cmd.encode('utf-8'))
    #2、拿命令的结果，并打印
    data=phone.recv(1024) #1024是一个坑
    print(data.decode('utf-8'))
phone.close()

服务端程序

# -*-coding：utf-8 -*-
# BY WANGCC
import socket
import subprocess

phone=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
# phone.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
phone.bind(('127.0.0.1',9901)) #0-65535:0-1024给操作系统使用
phone.listen(5)

print('starting...')
while True: # 链接循环
    conn,client_addr=phone.accept()
    print(client_addr)

    while True: #通信循环
        try:
            #1、收命令
            cmd=conn.recv(1024)
            if not cmd:break #适用于linux操作系统
            #2、执行命令，拿到结果
            obj = subprocess.Popen(cmd.decode('utf-8'), shell=True,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE)
            stdout=obj.stdout.read()
            stderr=obj.stderr.read()
            #3、把命令的结果返回给客户端
            print(len(stdout)+len(stderr))
            conn.send(stdout+stderr) #+是一个可以优化的点
        except ConnectionResetError: #适用于windows操作系统
            break
    conn.close()
phone.close()