在Python2.x中需要import SocketServer，在Python3.x中，都变成了小写，需要import sockerserver

Python Version: 3.5+

server.py

import socketserver

# 自定义socketserver需要继承socketserver.BaseRequestHandler
class MyServer(socketserver.BaseRequestHandler):

    # 每一个对象实例化的时候,都会执行handle里面的代码
    # 自定义的handle方法会重写父类的handle方法,主要用来与客户端进行交互
    def handle(self):
        conn = self.request
        # 这条欢迎消息会在每个客户端连上之后发送
        conn.sendall(bytes("Welcome to docs.20150509.cn", encoding='utf8'))
        while True:
            recv_data = conn.recv(1024)
            if len(recv_data) == 0:break
            conn.sendall(recv_data.upper())

if __name__ == "__main__":
    server = socketserver.ThreadingTCPServer(('127.0.0.1', 5959), MyServer)
    # 每多一个客户端的连接,就睡多起一个线程去处理
    server.serve_forever()

client.py

import socket

ip_port = ('127.0.0.1', 5959)
s = socket.socket()
s.connect(ip_port)

# 首先接收服务端发来的欢迎消息
welcome_msg = s.recv(1024)
print(str(welcome_msg, encoding='utf-8'))

while True:
    # 输入消息
    sent_data = input("> ").strip()
    if len(sent_data) == 0: continue
    #  发送消息
    s.send(bytes(sent_data, encoding='utf8'))

    # 接收消息
    recv_data = s.recv(1024)
    print(str(recv_data, encoding='utf-8'))

s.close()

执行

Welcome to docs.20150509.cn
> polarsnow
POLARSNOW
>

多个客户端可以同时连接使用，每个客户端连接时都会创建一个对象，在服务端都会新起一个进来来负责这个线程的处理

浅谈源码

我们就来看看继承的socketserver.BaseRequestHandler的源码

class BaseRequestHandler:

    """Base class for request handler classes.

    This class is instantiated for each request to be handled.  The
    constructor sets the instance variables request, client_address
    and server, and then calls the handle() method.  To implement a
    specific service, all you need to do is to derive a class which
    defines a handle() method.

    The handle() method can find the request as self.request, the
    client address as self.client_address, and the server (in case it
    needs access to per-server information) as self.server.  Since a
    separate instance is created for each request, the handle() method
    can define arbitrary other instance variariables.

    """

    def __init__(self, request, client_address, server):
        self.request = request
        self.client_address = client_address
        self.server = server
        self.setup()
        try:
            self.handle()
        finally:
            self.finish()

    def setup(self):
        pass

    def handle(self):
        pass

    def finish(self):
        pass

我没有省略，源码中只有这几行

可以看出，创建对象执行构造方法的时候，会自动去执行三个方法

self.setup() 负责客户端连接时的处理
self.handle() 负责客户端连接后的交互
self.finish() 负责客户端断开前的操作

在我们自己的类中，可以通过重写父类的这方法来实现对客户端请求的处理

Polar Snow Documentation

Python网络编程之socketserver的使用

浅谈源码