服务器：
 

import socket
from multiprocessing import Process
from threading import Thread

user_dic = {}


def send_recv(client_conn, client_addr):
    while 1:
        # 接收客户端发送的消息
        res = client_conn.recv(1024).decode("utf-8")
        print("客户端发送的消息：" + res)

        # 手动拼接用户字典中的key
        tu = ("127.0.0.1", int(res.split(":")[0]))

        # 通过key获得value   这个value是用户要发送的对方账户
        client_conn2 = user_dic.get(tu)
        # print("发送方：%s"% client_conn)
        # print("接收方：%s"% client_conn2)

        if client_conn2 is None:
            print("对方已下线！")
        else:
            message = "%s 账户对您说: %s \n" % (client_addr[1], res.split(":")[1])
            client_conn2.send(message.encode("utf-8"))


if __name__ == '__main__':

    # 创建tcp服务socket
    server_socket = socket.socket()

    # 绑定ip 端口
    server_socket.bind(("127.0.0.1", 9999))

    # 监听
    server_socket.listen()

    while 1:
        print("等待客户端连接....")
        # 接收客户端
        client_conn, client_addr = server_socket.accept()

        # 将接收到的信息存储到用户字典中
        user_dic[client_addr] = client_conn

        # 开启多进程
        Thread(target=send_recv, args=(client_conn, client_addr)).start()

客户端：
 

import socket
from multiprocessing import Process
from threading import Thread


def send_msg(client_socket):

    while 1:
        msg = input("请输入要发送的消息：\n")
        client_socket.send(msg.encode("utf-8"))


def recv_msg(client_socket):

    while 1:
        msg = client_socket.recv(1024).decode("utf-8")
        print(msg)


if __name__ == '__main__':

    client_socket = socket.socket()

    # 给客户端绑定id 端口
    client_socket.bind(("127.0.0.1", 8082))

    # 客户端连接服务器
    client_socket.connect(("127.0.0.1", 9999))
    print(client_socket.getsockname())


    Thread(target=send_msg,args=(client_socket,)).start()
    Thread(target=recv_msg, args=(client_socket,)).start()