python学习之网络编程

socket模块

小型服务器

import socket

s = socket.socket()

host = socket.gethostname()
port = 5000
s.bind((host, port))
s.listen(5)

while True:
c, addr = s.accept()   ##(clinet, address)
print 'get collection from ', addr
c.send('Thank you for connecting')
c.close()

小型客户机

import socket

s = socket.socket()

host = socket.gethostname()
port = 5000

s.connect((host, port))
print s.recv(1024)

urllib，urllib2模块

urlopen 返回的类文件对象支持close，read，readline，readlines方法，也支持迭代

from urllib import urlopen
webpage = urlopen('http://douban.com')
while True:
line = webpage.readline()
if not line:
break
webpage.close()

urlretrieve 获取远程文件并保存

urlretrieve('http://douban.com', '/tmp/douban.html')

SocketServer

类似于上面的服务器端代码

import SocketServer

class MyTCPHandler(SocketServer.BaseRequestHandler):
"""
The RequestHandler class for our server.

It is instantiated once per connection to the server, and must
override the handle() method to implement communication to the
client.
"""

def handle(self):
# self.request is the TCP socket connected to the client
self.data = self.request.recv(1024).strip()
print "%s wrote:" % self.client_address[0]
print self.data
# just send back the same data, but upper-cased
self.request.send(self.data.upper())

if __name__ == "__main__":
HOST, PORT = "localhost", 9999

# Create the server, binding to localhost on port 9999
server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)

# Activate the server; this will keep running until you
# interrupt the program with Ctrl-C
server.serve_forever()

使用SocketServer进行分叉和线程处理

分叉：并行时间，两份内存

线程：共享内存

带有select和poll的异步I/O

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