RequestHandler): def get(self): self.write("Hello, world") def make_app(): return tornado.web.Application([ (r"/", MainHandler), ]) async def main(): app = make_app() app.listen(8888) await asyncio.Event() generally causes some work to happen in the background before triggering some future action in the application (as opposed to normal synchronous functions, which do every- thing they are going to do before run(main()) 6.1.5 Structure of a Tornado web application A Tornado web application generally consists of one or more RequestHandler subclasses, an Application object which routes incoming requests to handlers

def get(self): self.write("Hello, world") def make_app(): return tornado.web.Application([ (r"/", MainHandler), ]) async def main(): app = make_app() app.listen(8888) spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Application classes tornado.template — Flexible background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler Handling request input Overriding RequestHandler

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) spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Application classes tornado.template — Flexible in the background Queue example - a concurrent web spider Structure of a Tornado web application The Application object Subclassing RequestHandler Handling request input Overriding RequestHandler methods

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) spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Application classes tornado.template — Flexible in the background Queue example - a concurrent web spider Structure of a Tornado web application The Application object Subclassing RequestHandler Handling request input Overriding RequestHandler methods

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) improved SSL support. In addition to the requirements which will be installed automatically by pip or setup.py install, the following optional packages may be useful: concurrent.futures [https://pypi.python spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Application classes tornado.template — Flexible

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 python versions). In addition to the requirements which will be installed automatically by pip or setup.py install, the following optional packages may be useful: • pycurl is used by the optional tornado cost of concurrent connections, Tornado uses a single-threaded event loop. This means that all application code should aim to be asynchronous and non-blocking because only one operation can be active at

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 improved SSL support. In addition to the requirements which will be installed automatically by pip or setup.py install, the following optional packages may be useful: • concurrent.futures is the recommended cost of concurrent connections, Tornado uses a single-threaded event loop. This means that all application code should aim to be asynchronous and non-blocking because only one operation can be active at

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) python versions). In addition to the requirements which will be installed automatically by pip or setup.py install, the following optional packages may be useful: pycurl [http://pycurl.sourceforge.net] spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Web framework tornado.web — RequestHandler and Application classes tornado.template — Flexible

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 cost of concurrent connections, Tornado uses a single-threaded event loop. This means that all application code should aim to be asynchronous and non-blocking because only one operation can be active at generally causes some work to happen in the background before triggering some future action in the application (as opposed to normal synchronous functions, which do every- thing they are going to do before

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 cost of concurrent connections, Tornado uses a single-threaded event loop. This means that all application code should aim to be asynchronous and non-blocking because only one operation can be active at generally causes some work to happen in the background before triggering some future action in the application (as opposed to normal synchronous functions, which do every- thing they are going to do before