Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado can scale to tens of thousands of open connections, making it ideal for long polling, WebSockets, and other applications that require a long-lived connection to each user.

Here is a simple "Hello, world" example web app for Tornado:

importtornado.ioloopimporttornado.webclassMainHandler(tornado.web.RequestHandler): defget(self): self.write("Hello, world") defmake_app(): returntornado.web.Application([ (r"/", MainHandler), ]) if__name__=="__main__": app=make_app() app.listen(8888) tornado.ioloop.IOLoop.current().start()

This example does not use any of Tornado's asynchronous features; for that see this simple chat room.

Documentation and links to additional resources are available at https://www.tornadoweb.org