Network programming of Python notes

1, to learn this part, you should first understand the OSI 7 layer model, TCP/IP four layer, socket sockets and other network-related knowledge points. Python network library, URLLIB,URLLIB2, the latter features a bit more powerful.

Import Urllib2import urllibresponse = Urllib2.urlopen (' http://www.baidu.com ') #获取百度首页的代码, open the remote file Urllib.urlretrieve (' Http://www.baidu.com ', ' baidu_index.html ')     #下载文件并保存到本地html = Response.read () print HTML

There are other modules, such as Smtplib,email,cgi,httplib,ftplib,cookie, are now available for inspection.
2,socket ModuleServer-side demo

Import sockets = Socket.socket () #host = Socket.gethostname () port = 1234s.bind ((host,port)) S.listen (5) while True:     C , addr = s.accept ()     print ' Client link from: ', addr     c.send (' Hello, client. This is server ')     c.close ()

the Socketserver module simplifies server-side programming.

From Socketserver import Tcpserver,streamrequesthandlerclass Handler (streamrequesthandler):d EF handle (self):     # Processing is placed in the handle method addr = Self.request.getpeername () print ' Get link from: ', Addrself.wfile.write (' Welcome, link succeed ') Server = TCPServer (("', 1234), Handler) Server.serve_forever () #begin to listen and handle link

#运行结果bowen: ~ bowen$ vimsocketserver_server.pybowen:~ bowen$ python socketserver_server.pyget link from: (' 192.168.42.184 ', 49533)

Client Demo

Import sockets = Socket.socket () host = Socket.gethostname () port = 1234s.connect ((host,port))     #连接服务器print S.recv ( 1024x768) S.close ()

Server and Client communication demo

bowen: Python bowen$ cat Server.pyimport socketsock = Socket.socket (socket.af_inet, socket. SOCK_STREAM) #create socketsock.bind ((' localhost ', 8001)) #bind IP and Portsock.listen (5) #start listeningwhile True: CONN,ADDR = sock.accept () print ' link from: ', Addrtry:conn.settimeout (5) Buff = CONN.RECV (1024x768) if buff = = ' 1 ': conn.send (' Welcome to Server ") #send msg to Clientelse:conn.send (' plead go out ') except Socket.timeout:print ' Time out exception ' Conn. Close () #close Linkbowen:python bowen$ cat client.pyimport socketimport timesock = Socket.socket () sock.connect (' localhost ', 8001)) Time.sleep (2) sock.send (' 1 ') print sock.recv (1024x768) #recv msg from Serversock.close () 

#运行结果bowen: ~ bowen$ vimsocketserver_server.pybowen:~ bowen$ python socketserver_server.pyget link from: (' 192.168.42.184 ', 49533)

3, asynchronous communication1, fork mode (forkingmixin); The server class provides multi-connection processing, and data transfer services.

From Socketserver import Tcpserver,forkingmixin,streamrequesthandlerclass Server (Forkingmixin, tcpserver):p Assclass Handler (streamrequesthandler):d EF handle (self): addr = Self.request.getpeername () print ' Get link from: ', Addrself.wfile.write (' Many links by fork ') if __name__ = = ' __main__ ': Server = Server (' localhost ', 1234), Handler) Server.serve_forever ()

2, Threading mode (ThreadingMixIn), similar to fork processing, except that the server inherits the ThreadingMixIn

From Socketserver import Tcpserver,threadingmixin,streamrequesthandlerclass Server (ThreadingMixIn, TCPServer): Passclass Handler (streamrequesthandler):d EF handle (self): addr = Self.request.getpeername () print ' Get link from: ', Addrself.wfile.write (' Many links in Thread ') if __name__ = = ' __main__ ': Server = Server ((' localhost ', 1234), Handler) Server.serve_forever ()

3, asynchronous I/O mode, the Select () method is used to monitor the specified file descriptor and respond when the descriptor changes. The poll () method can also be implemented.

Import socket, selects = Socket.socket () s.bind ((' localhost ', 1234)) S.listen (5) inputs = [s] #store socket reqwhile True:rs , Ws,es = Select.select (inputs,[],[]) #use Select () for R in Rs:if r is s:conn,addr = s.accept () print ' Get link form: ', Addrin Puts.append (conn) #put socket conn into  inputselse:try:    data = R.RECV (1024x768)    disconnected = not dataexcept Socket.error:    disconnected = Trueif disconnected:    print r.getpeername (), ' Disconnected '    inputs.remove (r ) Else:<span style= "White-space:pre" ></span>    print Data

Network programming of Python notes