Preliminary use of the Python Tornado framework-hello,world

Tornado is very simple to build, use Pip, or download source code can be.

Let's look at one of the simplest programs:

ImportTornado.ioloopImportTornado.webclassMainHandler (tornado.web.RequestHandler):defGet (self): Self.write ("") Application= Tornado.web.Application ([(R"/", MainHandler),])if __name__=='__main__': Application.listen (8888) tornado.ioloop.IOLoop.instance (). Start ()

We run this program and open the browser input:

http://localhost:8888/

You can see the bold HelloWorld.

So what does this piece of code mean:

Let's look first.

class MainHandler (Tornado.web.RequestHandler):     def Get (self):        self.write ("Hello,World")

This defines a processor that defines a GET method that corresponds to a GET request in the HTTP protocol.

Then it is:

application = Tornado.web.Application ([    (R"/", MainHandler),] )

The implication here is that if the user enters a path that is "/", that is, the root path, then the MainHandler we have just written will be used, if the request uses a GET, then call MainHandler's Get method, if it is a POST request, To call the Post method in MainHandler.

So we enter the above URL, tornado called the Get method in MainHandler, return "

Preliminary use of the Python Tornado framework-hello,world