Async HTTP Client, using Tornado, to fetch a list of URLs

fetch_urls_async.py

# The list of URLs is provide in an input file.
# (assuming one URL per line)
from tornado import httpclient
from tornado import gen 
from tornado.ioloop import IOLoop

class Fetcher:
    
        def __init__(self):
                self.client = httpclient.AsyncHTTPClient()

        @gen.coroutine
        def getPage(self, url):
                response = yield self.client.fetch(url)
                raise gen.Return(response)

def printPage(future_page):
        print future_page.result()

def makeRequest():
        fetcher = Fetcher()
        f = open('urls.txt', 'r')
        for url in f:
                IOLoop.current().add_future(fetcher.getPage(url.rstrip()), printPage)
        f.close()

if __name__ == "__main__":
        IOLoop.instance().add_callback(makeRequest)
        IOLoop.instance().start()