[Python] Find download links to all PragPub magazines

pragpub_get.py

#!/usr/bin/env python

"""
find download links to all PragPub magazines

usage:
    $ ./pragpub_get.py [pdf | html | epub | mobi] > pragpub.lst
    $ wget -c -i pragpub.lst

written by Mathias Lafeldt <mathias.lafeldt@gmail.com>
"""

import sys, re, urllib

if len(sys.argv) > 1:
    ext = sys.argv[1]
else:
    ext = 'pdf'

url = 'http://pragprog.com/magazines'
pattern = re.compile(r'"(%s/download/.+?\.%s)"' % (url, ext), flags=re.IGNORECASE)
page = 1

while True:
    html = urllib.urlopen(url + '?page=' + str(page)).read()
    links = pattern.findall(html)
    if not links:
        break
    for l in links:
        print urllib.urlopen(l).geturl()
    page += 1