python網絡編程：一、前言及socket初探

在知乎上看到有人提問， Python 網絡編程需要學習哪些網絡相關的知識？，看了下，覺得還挺有道理。主要的觀點如下：

 

Python網絡編程是一個很大的范疇，個人感覺需要掌握的點有：  

1. 如何使用Python來創建socket, 如何將socket與指定的IP地址和端口進行綁定，使用socket來發送數據，接受數據， 
2. 如何使用Python中處理線程，從而編寫可以同時處理多個請求的web服務器 
3.  如何使用Python來控制HTTP層的邏輯，包括如何創建http GET,POST,PUT,DELETE請求，如何處理接受到的HTTP請求，這些分別涉及python的httplib, basehttpserver等模塊    
4. 掌握一種基本的python的web開發框架，比如webpy, django,pylon 
5.  了解非阻塞式的HTTP Server,比如tornado 
6. 了解twisted, python編寫的消息驅動的網絡引擎 

 

參考資料:

網絡基礎知識

1. HTTP: the definitive guide http://www.amazon.com/HTTP-Definitive-Guide-David-Gourley/dp/1565925092/
2. Computer Networking: A Top-Down Approach http://www.amazon.com/Computer-Networking-Top-Down-Approach-Edition/dp/0136079679/ref

 

python 網絡編程基礎         

1. python 網絡編程 http://www.amazon.com/Foundations-Python-Network-Programming-Goerzen/dp/1590593715 
2. python socket編程的文檔 http://docs.python.org/library/socket.html 
3. python httplib的文檔 http://docs.python.org/library/httplib.html

 

python常用框架文檔:          

1. django 的官方網站 https://www.djangoproject.com/ 
2. twisted 的官方網站 http://twistedmatrix.com/trac/ 
3. tornado 的官方網站 http://www.tornadoweb.org/

 

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學了一下python的socket

 

socket概念：

      通常也稱作"套接字"，用於描述IP地址和端口，是一個通信鏈的句柄。在Internet上的主機一般運行了多個服務軟件，同時提供幾種服務。每種服務都打開一個Socket，並綁定到一個端口上，不同的端口對應於不同的服務。Socket正如其英文原意那樣，象一個多孔插座。一台主機猶如布滿各種插座的房間，每個插座有一個編號，有的插座提供220伏交流電， 有的提供110伏交流電，有的則提供有線電視節目。 客戶軟件將插頭插到不同編號的插座，就可以得到不同的服務。

 

主要用到的模塊： socket

• 建立新的socket：socket.socket([family[, type[, proto]]])
• 獲取遠程服務器ip：socket.gethostbyname(host)
• 連接到一個遠程套接字地址：socket.connect(address) 
• 向socket發送數據：socket.sendall(string[, flags]) 
• 從socket接受數據：socket.recv(bufsize[, flags]) 

• Bind the socket to address.： socket.bind(address) 
• Listen for connections made to the socket. ：socket.listen(backlog) 

 

以下代碼主要參考這個教程： http://www.binarytides.com/python-socket-programming-tutorial/

客戶端：

 

# clientsocket.py

import socket

def Main():
    try:
        # Address Family : AF_INET (this is IP version 4 or IPv4)
        # Type :  SOCK_STREAM (this means connection oriented TCP protocol)
        #         SOCK_DGRAM indicates the UDP protocol. 
        new_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    except socket.error, msg:
        print 'Failed to creat socket. Error code:', str(msg[0]), 
        print 'Error message:', msg[1]
        return
    print 'Socket Created'
    
    host = 'www.baidu.com'
    port = 80
    try:
        remote_ip = socket.gethostbyname(host)
    except socket.gaierror:
        print 'Hostname could not be resolved. Exiting.'
        return 
    print 'Ip address of', host, 'is', remote_ip
    
    # Connect to remote server
    new_socket.connect((host, port))
    print 'Socket Connected to', host, 'on ip', remote_ip
    
    # Send some data to remote server | socket.sendall(string[, flags]) 
    message = 'GET / HTTP/1.1\r\n\r\n'
    try:
        new_socket.sendall(message)
    except socket.error:
        print 'Send fail.'
        return 
    print 'Message send successfully.'

    # Receive data | socket.recv(bufsize[, flags]) 
    reply = new_socket.recv(4096)
    print reply
    
    # Close the socket
    new_socket.close()
    
    
if __name__ == '__main__':
    Main()

 

服務器端：

 

• Bind the socket to address.： socket.bind(address) 
• Listen for connections made to the socket. ：socket.listen(backlog) 

#! /usr/bin/env python

# serversockethand.py

"""
To handle every connection we need a separate handling code to run along 
with the main server accepting connections. One way to achieve this is 
using threads. The main server program accepts a connection and creates
a new thread to handle communication for the connection, and then the
 server goes back to accept more connections.
"""

import socket
import thread

def Main():
    HOST = ''
    PORT = 8888
    
    new_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    print 'Socket created.'
    
    # Bind socket to local host and port 
    try:
        new_socket.bind((HOST, PORT))
    except socket.error, msg:
        print 'Bind failed. Error code:', str(msg[0]) + 'Message' + msg[1]
        return 
    print 'Socket bind complete'

    # Listening on socket
    new_socket.listen(10)
    print 'Socket now listening..'
    
    # Now keep talking with client
    while 1:
        # Wait to accept a connection 
        conn, addr = new_socket.accept()
        print 'Connected with', addr[0], ':', str(addr[1])
        
        thread.start_new_thread(clientThread, (conn, ))
    
    new_socket.close()
    
    
# Function for handling connections. This will be used to create threads.
def clientThread(conn):
    # Sending message to connected client
    conn.send('Welcome to the server. Type something and hit enter\n')
    
    while 1:
        data = conn.recv(1024)
        if not data:
            break
        reply = 'OK..' + data
        conn.sendall(reply)
    
    conn.close()
    

if __name__ == '__main__':
    Main()