WORLD Here is a simple “Hello, world” example web app for Tornado: import asyncio import tornado class MainHandler(tornado.web.RequestHandler): def get(self): self.write("Hello, world") def make_app(): generator as the result of the yield expression. Most asyn- chronous code never touches the Future class directly except to immediately pass the Future returned by an asyn- chronous function to a yield expression def remove_fragment(url): pure_url, frag = urldefrag(url) return pure_url def get_links(html): class URLSeeker(HTMLParser): def __init__(self): HTMLParser.__init__(self) self.urls = [] def handle_starttag(self

world Here is a simple “Hello, world” example web app for Tornado: import asyncio import tornado class MainHandler(tornado.web.RequestHandler): def get(self): self.write("Hello, world") generator as the result of the yield expression. Most asynchronous code never touches the Future class directly except to immediately pass the Future returned by an asynchronous function to a yield expression remove_fragment(url): pure_url, frag = urldefrag(url) return pure_url def get_links(html): class URLSeeker(HTMLParser): def __init__(self): HTMLParser.__init__(self)

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 483 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 483 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 483 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 483 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 483 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 483 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 495 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 495 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 494 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 494 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 494 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 494 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 494 37.5 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 494 37.6 Avoid strange type Unions

methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Variables 10 4.1 Allowed Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2 Assignment expressions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.5 Operators With Special Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 9.6 Anonymous Functions . . . . . . excess argument diversity in the caller . . . . . . . . . . . . . . . . . . . . 494 37.6 Append ! to names of functions that modify their arguments . . . . . . . . . . . . . 495 37.7 Avoid strange type Unions