py python threading concurrent

import concurrent.futures

import urllib.request



URLS = ['http://www.foxnews.com/',

        'http://www.cnn.com/',

        'http://europe.wsj.com/',

        'http://www.bbc.co.uk/',

        'http://www.cnn.com/']



# Retrieve a single page and report the URL and contents

def load_url(url, timeout):

    with urllib.request.urlopen(url, timeout=timeout) as conn:

        return conn.read()



# We can use a with statement to ensure threads are cleaned up promptly

with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:

    # Start the load operations and mark each future with its URL

    future_to_url = {executor.submit(load_url, url, 60): url for url in URLS}

    for future in concurrent.futures.as_completed(future_to_url):

        url = future_to_url[future]

        try:

            data = future.result()

        except Exception as exc:

            print('%r generated an exception: %s' % (url, exc))

        else:

            print('%r page is %d bytes' % (url, len(data)))