python网络编程：一、前言及socket初探

在知乎上看到有人提问，Python 网络编程需要学习哪些网络相关的知识？，看了下，觉得还挺有道理。主要的观点如下：

 

Python网络编程是一个很大的范畴，个人感觉需要掌握的点有：  

1. 如何使用Python来创建socket, 如何将socket与指定的IP地址和端口进行绑定，使用socket来发送数据，接受数据， 
2. 如何使用Python中处理线程，从而编写可以同时处理多个请求的web服务器 
3.  如何使用Python来控制HTTP层的逻辑，包括如何创建http GET,POST,PUT,DELETE请求，如何处理接受到的HTTP请求，这些分别涉及python的httplib, basehttpserver等模块    
4. 掌握一种基本的python的web开发框架，比如webpy, django,pylon 
5.  了解非阻塞式的HTTP Server,比如tornado 
6. 了解twisted, python编写的消息驱动的网络引擎 

 

参考资料:

网络基础知识

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 网络编程基础         

1. python 网络编程 http://www.amazon.com/Foundations-Python-Network-Programming-Goerzen/dp/1590593715 
2. python socket编程的文档 http://docs.python.org/library/socket.html 
3. python httplib的文档 http://docs.python.org/library/httplib.html

 

python常用框架文档:          

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

 

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学了一下python的socket

 

socket概念：

      通常也称作"套接字"，用于描述IP地址和端口，是一个通信链的句柄。在Internet上的主机一般运行了多个服务软件，同时提供几种服务。每种服务都打开一个Socket，并绑定到一个端口上，不同的端口对应于不同的服务。Socket正如其英文原意那样，象一个多孔插座。一台主机犹如布满各种插座的房间，每个插座有一个编号，有的插座提供220伏交流电， 有的提供110伏交流电，有的则提供有线电视节目。 客户软件将插头插到不同编号的插座，就可以得到不同的服务。

 

主要用到的模块： socket

• 建立新的socket：socket.socket([family[, type[, proto]]])
• 获取远程服务器ip：socket.gethostbyname(host)
• 连接到一个远程套接字地址：socket.connect(address) 
• 向socket发送数据：socket.sendall(string[, flags]) 
• 从socket接受数据：socket.recv(bufsize[, flags]) 

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

 

以下代码主要参考这个教程：http://www.binarytides.com/python-socket-programming-tutorial/

客户端：

 

# 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()

 

服务器端：

 

• 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()