This allows you to write code as if it were synchronous, and not worry about callbacks at all. You also don't have to use any special patterns, such as writing everything as a generator.
Overall this allows you to structure your program in a much more sensible, straightforward way. It's also immensely helpful when porting synchronous code to Tornado.
Derived from this blog article: http://blog.joshhaas.com/2011/06/marrying-boto-to-tornado-greenlets-bring-them-together/
import tornado.web from greenlet_tornado import greenlet_asynchronous, greenlet_fetch class ExampleHandler(tornado.web.RequestHandler): @greenlet_asynchronous def get(self): # ... self.helper() # ... self.write("Hello World!") def helper(self): # Fetch something. greenlet_fetch() will block until the request is complete, # but the tornado IOLoop can do other things in the meantime. http_response = greenlet_fetch("http://www.mopub.com") # ... Do something with the response ...