网络编程的专利权应该属于Unix，各个平台（如windows、Linux等）、各门语言（C、C++、Python、Java等）所实现的符合自身特性的语法都大同小异。在我看来，懂得了Unix的socket网络编程，其他的形式的网络编程方法也就知道了。这句话说得还不太严谨。准确的应该说成懂得了socket编程的原理，网络编程也就知道了，不同之处就在于每个平台，每个语言都有自己专享的语法，我们直接灵活套用就行了。
下面是用python实现的最基本的网络编程的例子，即依托于客户端-服务器的架构，实现客户端与服务器之间的单向“数据流通”。我们分别用两个方法来实现，一个方法是最原始的socket编程，另一个方法是利用python的面向对象对第一种方法进行封装实现，目的是减少实现透明性，便于快速开发。
要求：客户端输入数据，发送到服务端，服务器端生成（时间戳+数据）的封装数据回应客户端。由于socket编程包括两种：面向连接的和无连接的，这两种分别对应TCP数据流和UDP数据报文。所以，我们两种方法都进行实现。
一、Python socket编程
面向连接的TCP socket编程：
1 # -*- coding: utf-8 -*- 2 3 from socket import * 4 from time import ctime 5 6 # Address and Port 7 HOST = '' 8 PORT = 21567 9 ADDR = (HOST, PORT)10 11 # BuffSize12 BUFSIZ = 102413 14 # build socket15 tcpSerSock = socket(AF_INET, SOCK_STREAM)16 # bind socket17 tcpSerSock.bind(ADDR)18 # listen 5 client 19 tcpSerSock.listen(5)20 21 try:22 while True:23 print 'waiting for connection...'24 # build client socket25 tcpCliSock, addr = tcpSerSock.accept()26 print '...connect from:', addr27 28 # accept data and process29 while True:30 data = tcpCliSock.recv(BUFSIZ)31 if not data:32 break33 tcpCliSock.send('[%s] %s' % (ctime(), data))34 35 # close client socket 36 tcpCliSock.close()37 except EOFError, KeyboardInterrupt:38 tcpSerSock.close() 1 # -*- coding:utf-8 -*- 2 3 from socket import * 4 5 # Address and Port 6 HOST = '127.0.0.1' 7 PORT = 21567 8 ADDR = (HOST, PORT) 9 10 # BufferSize11 BUFSIZ = 102412 13 #build socket 14 tcpCliSocket = socket(AF_INET, SOCK_STREAM)15 tcpCliSocket.connect(ADDR)16 17 while True:18 data = raw_input('> ')19 if not data:20 break21 # send data22 tcpCliSocket.send(data)23 # recv data24 data = tcpCliSocket.recv(BUFSIZ)25 if not data:26 break27 # show data28 print data29 tcpCliSocket.close() 无连接的UDP socket编程
1 # -*- coding: utf-8 -*- 2 3 from socket import * 4 from time import ctime 5 6 # Address and Port 7 HOST = '' 8 PORT = 8000 9 ADDR = (HOST, PORT)10 11 # BufferSize12 BUFFSIZE = 102413 # build socket14 udpSerSock = socket(AF_INET, SOCK_DGRAM)15 # bind socket16 udpSerSock.bind(ADDR)17 18 try:19 while True:20 print 'waiting the message...'21 data, addr = udpSerSock.recvfrom(BUFFSIZE)22 print 'received the message: '+data+' from: ', addr23 udpSerSock.sendto('[%s] %s' % (ctime(), data), addr)24 except EOFError, KeyboardInterrupt:25 udpSerSock.close() 1 # -*- coding: utf-8 -*- 2 3 from socket import * 4 5 # Address and Port 6 HOST = 'localhost' 7 PORT = 8000 8 ADDR = (HOST, PORT) 9 10 # BufferSize11 BUFSIZ = 102412 13 # build socket 14 udpCliSock = socket(AF_INET, SOCK_DGRAM)15 16 while True:17 data = raw_input('> ')18 udpCliSock.sendto(data, ADDR)19 data = udpCliSock.recvfrom(BUFSIZ)20 if not data:21 break22 print data 23 udpCliSock.close() 二、基于封装类SocketServer的网络编程
1 # -*- coding: utf-8 -*- 2 3 from SocketServer import TCPServer as TCP, StreamRequestHandler as SRH 4 from time import ctime 5 6 # Address and Port 7 HOST = '' 8 PORT = 21567 9 ADDR = (HOST, PORT)10 11 # BuffSize12 BUFSIZ = 102413 14 # build RequestHandler15 class MyRequestHandler(SRH):16 def handle(self):17 print '...connected from: ', self.client_address18 self.wfile.write('[%s] %s' % (ctime(), self.rfile.readline()))19 20 # build TCPServer21 TCPServ = TCP(ADDR, MyRequestHandler)22 print 'waiting for connection...'23 # loop to process24 TCPServ.serve_forever() 1 # -*- coding:utf-8 -*- 2 3 from socket import * 4 5 # Address and Port 6 HOST = '127.0.0.1' 7 PORT = 21567 8 ADDR = (HOST, PORT) 9 10 # BufferSize11 BUFSIZ = 102412 13 while True:14 # note: SocketServer 的请求处理器的默认行为是接受连接，15 # 得到请求，然后就关闭连接，所以需要多次连接16 tcpCliSock = socket(AF_INET, SOCK_STREAM)17 tcpCliSock.connect(ADDR)18 19 # process data20 data = raw_input('> ')21 if not data:22 break23 tcpCliSock.send('%s\r\n' % data)24 25 data = tcpCliSock.recv(BUFSIZ)26 if not data:27 break28 print data.strip()29 tcpCliSock.close()