python網絡編程初級

網絡編程的專利權應該屬於Unix，各個平台（如windows、Linux等）、各門語言（C、C++、Python、Java等）所實現的符合自身特性的語法都大同小異。在我看來，懂得了Unix的socket網絡編程，其他的形式的網絡編程方法也就知道了。這句話說得還不太嚴謹。准確的應該說成懂得了socket編程的原理，網絡編程也就知道了，不同之處就在於每個平台，每個語言都有自己專享的語法，我們直接靈活套用就行了。

下面是用python實現的最基本的網絡編程的例子，即依托於客戶端-服務器的架構，實現客戶端與服務器之間的單向“數據流通”。我們分別用兩個方法來實現，一個方法是最原始的socket編程，另一個方法是利用python的面向對象對第一種方法進行封裝實現，目的是減少實現透明性，便於快速開發。

要求：客戶端輸入數據，發送到服務端，服務器端生成（時間戳+數據）的封裝數據回應客戶端。由於socket編程包括兩種：面向連接的和無連接的，這兩種分別對應TCP數據流和UDP數據報文。所以，我們兩種方法都進行實現。

 

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一、Python socket編程

面向連接的TCP socket編程：

# -*- coding: utf-8 -*-

from socket import *
from time import ctime 

# Address and Port
HOST = ''
PORT = 21567
ADDR = (HOST, PORT)

# BuffSize
BUFSIZ = 1024

# build socket
tcpSerSock = socket(AF_INET, SOCK_STREAM)
# bind socket
tcpSerSock.bind(ADDR)
# listen 5 client 
tcpSerSock.listen(5)

try:
    while True:
        print 'waiting for connection...'
        # build client socket
        tcpCliSock, addr = tcpSerSock.accept()
        print '...connect from:', addr

        # accept data and process
        while True:
            data = tcpCliSock.recv(BUFSIZ)
            if not data:
                break
            tcpCliSock.send('[%s] %s' % (ctime(), data))

            # close client socket 
            tcpCliSock.close()
except EOFError, KeyboardInterrupt:
    tcpSerSock.close()

# -*- coding:utf-8 -*-

from socket import *

# Address and Port 
HOST = '127.0.0.1'
PORT = 21567
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

#build socket 
tcpCliSocket = socket(AF_INET, SOCK_STREAM)
tcpCliSocket.connect(ADDR)

while True:
    data = raw_input('> ')
    if not data:
        break
    # send data
    tcpCliSocket.send(data)
    # recv data
    data = tcpCliSocket.recv(BUFSIZ)
    if not data:
        break
    # show data
    print data
tcpCliSocket.close()

無連接的UDP socket編程

# -*- coding: utf-8 -*-

from socket import *
from time import ctime 

# Address and Port 
HOST = ''
PORT = 8000
ADDR = (HOST, PORT)

# BufferSize
BUFFSIZE = 1024
# build socket
udpSerSock = socket(AF_INET, SOCK_DGRAM)
# bind socket
udpSerSock.bind(ADDR)

try:
    while True:
        print 'waiting the message...'
        data, addr = udpSerSock.recvfrom(BUFFSIZE)
        print 'received the message: '+data+' from: ', addr
        udpSerSock.sendto('[%s] %s' % (ctime(), data), addr)
except EOFError, KeyboardInterrupt:
    udpSerSock.close()

# -*- coding: utf-8 -*-

from socket import *

# Address and Port 
HOST = 'localhost'
PORT = 8000
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

# build socket 
udpCliSock = socket(AF_INET, SOCK_DGRAM)

while True:
    data = raw_input('> ')
    udpCliSock.sendto(data, ADDR)
    data = udpCliSock.recvfrom(BUFSIZ)
    if not data:
        break
    print data 
udpCliSock.close()

二、基於封裝類SocketServer的網絡編程

# -*- coding: utf-8 -*-

from SocketServer import TCPServer as TCP, StreamRequestHandler as SRH 
from time import ctime 

# Address and Port
HOST = ''
PORT = 21567
ADDR = (HOST, PORT)

# BuffSize
BUFSIZ = 1024

# build RequestHandler
class MyRequestHandler(SRH):
    def handle(self):
        print '...connected from: ', self.client_address
        self.wfile.write('[%s] %s' % (ctime(), self.rfile.readline()))

# build TCPServer
TCPServ = TCP(ADDR, MyRequestHandler)
print 'waiting for connection...'
# loop to process
TCPServ.serve_forever()

# -*- coding:utf-8 -*-

from socket import *

# Address and Port 
HOST = '127.0.0.1'
PORT = 21567
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

while True:
    # note: SocketServer 的請求處理器的默認行為是接受連接，
    # 得到請求，然后就關閉連接，所以需要多次連接
    tcpCliSock = socket(AF_INET, SOCK_STREAM)
    tcpCliSock.connect(ADDR)

    # process data
    data = raw_input('> ')
    if not data:
        break
    tcpCliSock.send('%s\r\n' % data)

    data = tcpCliSock.recv(BUFSIZ)
    if not data:
        break
    print data.strip()
    tcpCliSock.close()