Python tornado example pdf

Python tornado example pdf

I'd be happy to help you with that! Here is a comprehensive guide to building a web application using Tornado, a Python web framework, in the form of a PDF:

Tornado Tutorial: Building a Web Application

Introduction

Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking I/O, Tornado provides good support for handling hundreds or thousands of open connections concurrently.

Getting Started with Tornado

To start building your web application with Tornado, you'll need to have Python 3.6+ installed on your machine. You can install the latest version of Tornado using pip:

pip install tornado

Once installed, let's create a new project directory and initialize our Tornado project with the following command:

mkdir my_tornado_app
cd my_tornado_app
tornado -i .

This will generate a basic directory structure for our project.

Basic Concepts

Before we dive into building our application, it's essential to understand some of the fundamental concepts in Tornado. These include:

Building Our Application

Let's start by creating a simple "Hello World" application:

import tornado.ioloop
import tornado.web
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, World!")
def make_app():
return tornado.web.Application([
(r"/", MainHandler),
])
if name == "main":
app = make_app()
app.listen(8888)
tornado.ioloop.IOLoop.current().start()

This code defines a single route for our application, which responds to GET requests with the string "Hello, World!". We then create an instance of our Tornado Application and listen on port 8888.

Handling Requests

Now that we have a basic application up and running, let's look at how we can handle different types of requests. In Tornado, requests are handled using methods in your Handler class. Here's an example of a simple route handler:

class MyHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello from GET request!")
def post(self):
self.write("Hello from POST request!")

This code defines two routes: one for GET requests and another for POST requests. Each route handles its respective type of request differently.

Asynchronous Programming

One of the key features that sets Tornado apart is its support for asynchronous programming. In Tornado, we use coroutines (functions that can suspend execution) to handle asynchronous operations:

import tornado.gen
class MyHandler(tornado.web.RequestHandler):
@tornado.gen.coroutine
def get(self):
yield do_something_async()
self.write("Hello from GET request!")
@tornado.gen.coroutine
def do_something_async():
perform some async operation here...
pass

In this example, our get method uses a coroutine to handle an asynchronous operation. This allows our application to remain responsive while waiting for the operation to complete.

Conclusion

Tornado is a powerful and flexible Python web framework that makes it easy to build high-performance web applications. By using non-blocking I/O and coroutines, we can write efficient, scalable code that handles multiple connections concurrently.

In this tutorial, we've covered the basics of building a Tornado application, from installing the framework to handling requests asynchronously. With this foundation, you're ready to start building your own web applications with Tornado!

Python tornado example github

I'd be happy to respond in English.

Python Tornado Example on GitHub

If you're looking for a Python Tornado example on GitHub, I've got some great resources to share with you!

For those who are new to Tornado, it's a Python web framework that allows you to write asynchronous applications using the async and await syntax. It was developed by Facebook and is now an open-source project.

Example 1: A Simple Web Server

Here's an example of how to use Tornado to create a simple web server:

https://github.com/tornadoweb/tornado/blob/master/demos/httpserver.py

This code defines a class called RequestHandler, which inherits from tornado.web.RequestHandler. The get method is called when the user requests the URL /hello.

class RequestHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, Tornado!")
if name == "main":
application = tornado.web.Application([(r"/hello", RequestHandler)])
http_server = tornado.httpserver.HTTPServer(application)
http_server.listen(8888)
tornado.ioloop.IOLoop.instance().start()

Example 2: A Chat Server

Here's an example of how to use Tornado to create a simple chat server:

https://github.com/tornadoweb/tornado/blob/master/demos/chat.py

This code defines two classes, ChatHandler and Client, which are used to handle incoming connections and outgoing messages.

class ChatHandler(tornado.web.RequestHandler):
def get(self):
self.write("Welcome to the chat room!")
def post(self):
message = self.get_argument('message', '')
self.write(message)
class Client(tornado.tcp.Client):
def connected(self, transport):
while True:
data = self.read_bytes(1024)
if not data:
break
self.transport.write(data)
if name == "main":
application = tornado.web.Application([(r"/", ChatHandler)])
server = tornado.tcpserver.TCPServer()
client = Client()
client.connect('localhost', 8888, handler=client.connected)
http_server = tornado.httpserver.HTTPServer(application)
http_server.listen(8888)
tornado.ioloop.IOLoop.instance().start()

These are just a couple of examples to get you started with Tornado. There are many more features and capabilities that make Tornado an excellent choice for building scalable, asynchronous web applications!

More Resources

I hope this helps!