IBM's python threading example with Queues

ibm_queue.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import Queue
import threading
import urllib2
import time

hosts = ['http://yahoo.com', 'http://google.com', 'http://amazon.com',
         'http://ibm.com', 'http://apple.com']

queue = Queue.Queue()


class ThreadUrl(threading.Thread):

    """Threaded Url Grab"""

    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.queue = queue

    def run(self):
        while True:

        # grabs host from queue

            host = self.queue.get()

        # grabs urls of hosts and prints first 1024 bytes of page

            url = urllib2.urlopen(host)
            print url.read(1024)

        # signals to queue job is done

            self.queue.task_done()


start = time.time()


def main():

    # spawn a pool of threads, and pass them queue instance

    for i in range(5):
        t = ThreadUrl(queue)
        t.setDaemon(True)
        t.start()

    # populate queue with data

        for host in hosts:
            queue.put(host)

    # wait on the queue until everything has been processed

    queue.join()


main()
print 'Elapsed Time: %s' % (time.time() - start)