python网络编程初级

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 # BuffSize

12 BUFSIZ = 1024

13 

14 # build socket

15 tcpSerSock = socket(AF_INET, SOCK_STREAM)

16 # bind socket

17 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 socket

25         tcpCliSock, addr = tcpSerSock.accept()

26         print '...connect from:', addr

27 

28         # accept data and process

29         while True:

30             data = tcpCliSock.recv(BUFSIZ)

31             if not data:

32                 break

33             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 # BufferSize

11 BUFSIZ = 1024

12 

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         break

21     # send data

22     tcpCliSocket.send(data)

23     # recv data

24     data = tcpCliSocket.recv(BUFSIZ)

25     if not data:

26         break

27     # show data

28     print data

29 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 # BufferSize

12 BUFFSIZE = 1024

13 # build socket

14 udpSerSock = socket(AF_INET, SOCK_DGRAM)

15 # bind socket

16 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: ', addr

23         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 # BufferSize

11 BUFSIZ = 1024

12 

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         break

22     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 # BuffSize

12 BUFSIZ = 1024

13 

14 # build RequestHandler

15 class MyRequestHandler(SRH):

16     def handle(self):

17         print '...connected from: ', self.client_address

18         self.wfile.write('[%s] %s' % (ctime(), self.rfile.readline()))

19 

20 # build TCPServer

21 TCPServ = TCP(ADDR, MyRequestHandler)

22 print 'waiting for connection...'

23 # loop to process

24 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 # BufferSize

11 BUFSIZ = 1024

12 

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 data

20     data = raw_input('> ')

21     if not data:

22         break

23     tcpCliSock.send('%s\r\n' % data)

24 

25     data = tcpCliSock.recv(BUFSIZ)

26     if not data:

27         break

28     print data.strip()

29     tcpCliSock.close()