stormy-webber

Tornado

• Fast web server that supports non-blocking I/O
• Developed at FriendFeed, open sourced at Facebook in 2009
• Long polling, WebSockets etc.
• Pure Python

Tornado cont.

• Not a framework.
• Usual "framework" features, sessions, auth, templates etc.
• Support for callbacks, coroutines and futures (Tulipish)

Stringing cats

• ioloop.add_callback, ioloop.add_future
• gen.coroutine, gen.Task, gen.Wait

e.g.

result = yield motor.Op(db.messages.insert, {'msg': msg})

# vs.

db.messages.insert(
    {'msg': msg},
    callback=self._on_response)

Great for RESTful webservices

e.g.

import tornado.web
from sys import exit

from .handlers import ResourceHandler

def main():
    application = tornado.web.Application((
    (r"/resources/", ResourceHandler, "resources-root")
    ),)

    application.listen(port=8888, address='0.0.0.0')
    return tornado.ioloop.IOLoop.instance().start()

if __name__ == "__main__":
    exit(main())

e.g.

import time
from tornado.web import asynchronous, RequestHandler

class ResourceHandler(RequestHandler):
    def prepare(self):
    self.user_id = self.get_argument('user')

    @asynchronous
    def get(self):
    tornado.ioloop.IOLoop.instance().add_timeout(
        time.time()+60, self._end)

    def _end(self):
    self.finish('hello world!')

Best tool for the job

• Can be mixed freely with other libraries
• Mostly useful if there is an async library available for your backend component
• If you want socket.io support gevent has a better library etc.

Batteries included

• Templating, auth handlers (including Twitter OAuth LOL)
• HTTP client / server
• TCP client / server (Streams)

Batteries included cont.

• Thread pools
• Async DNS (c-ares, threads, TwistedResolver)
• Process pooling with bound master socket/port

Batteries included cont.

• tornado.platform.twisted
• WebSockets / Longpolling
• SMTP client

trequests

• Use libraries that use python-requests for HTTP
• Use Tornado's AsyncHTTPClient/CurlAsyncHTTPClient instead of httplib3
• Caveat: does require greenlet

trequests cont.

"""bobs_big_data.py"""
import requests

class BigData(object):
    ...

    def post(self):
        r = requests.post(self.url, data=self.data)
        return r.json()

trequests cont.

import bobs_big_data
from tornado.web import RequestHandler
from trequests import setup_session
from tornalet import tornalet

setup_session()

class WebHandler(RequestHandler):
    @tornalet
    def get(self):
        data = {'foo': 'bar'}
        response = bobs_big_data.BigData(data).post()
        return self.write(response)

trequests cont.

github.com/1stvamp/trequests

sys.exit(0)

• Slides: github.com/1stvamp/stormy-webber

^D

• Jonathan "Joff" Oliver: about.me/joffie
• Grab me and say hi :-)