. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2 API Reference 41 2.1 API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Documentation, Release 1.2.dev0 click is a Python package for creating beautiful command line interfaces in a composable way with as little amount of code as necessary. It’s the “Command Line Interface tools fun and quick without causing user frustration at not being able to implement an intended CLI API. Click in three points: • arbitrary nesting of commands • automatic help page generation • supports

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue get(self): http = tornado.httpclient.AsyncHTTPClient() response = await http.fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) (continues on next page) 26 Chapter

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do everything they are going to do before returning). There are many styles of asynchronous interfaces: Callback argument Return a placeholder (Future, Promise, Deferred) Deliver to a queue Callback - api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") For

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2 API Reference 49 2.1 API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Click Documentation, Release 2.6 Click is a Python package for creating beautiful command line interfaces in a composable way with as little code as neces- sary. It’s the “Command Line Interface Creation and fun while also preventing any frustration caused by the inability to implement an intended CLI API. Click in three points: • arbitrary nesting of commands • automatic help page generation • supports

which do everything they are going to do before returning). There are many styles of asynchronous interfaces: Callback argument Return a placeholder (Future, Promise, Deferred) Deliver to a queue Callback simply raise an exception (as opposed to the ad-hoc error handling common in callback-oriented interfaces), and Futures lend themselves well to use with coroutines. Coroutines will be discussed in depth else the user’s browser will simply hang. Here is an example that makes a call to the FriendFeed API using Tornado’s built-in AsyncHTTPClient: class MainHandler(tornado.web.RequestHandler): @tornado

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") For a more advanced

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") 26 Chapter 6. Documentation

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") 26 Chapter 6. Documentation

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") 26 Chapter 6. Documentation

it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe which do every- thing they are going to do before returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue fetch("http://friendfeed-api.com/v2/feed/bret") json = tornado.escape.json_decode(response.body) self.write("Fetched " + str(len(json["entries"])) + " entries " "from the FriendFeed API") 26 Chapter 6. DocumentationTornado