How can I speed up fetching pages with urllib2 in python?

Question

I have a script that fetches several web pages and parses the info.

(An example can be seen at http://bluedevilbooks.com/search/?DEPT=MATH&CLASS=103&SEC=01 )

Answer 1

Since this question was posted it looks like there's a higher level abstraction available, ThreadPoolExecutor:

https://docs.python.org/3/library/concurrent.futures.html#threadpoolexecutor-example

The example from there pasted here for convenience:

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://some-made-up-domain.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)))

There's also map which I think makes the code easier: https://docs.python.org/3/library/concurrent.futures.html#concurrent.futures.Executor.map