mag2bt.py

#!/usr/bin/env python

import re
import sys

if sys.version_info[0] == 2:
    import urllib2
    import urllib
    import urlparse
    input = raw_input
else:
    import urllib.request as urllib2
    import urllib.parse as urllib
    urlparse = urllib


def input_url():
    if len(sys.argv) == 1:
        url = input('Enter url --> ')
    else:
        url = sys.argv[1]
    return url


def parse(url):
    sfx = '.torrent'
    ptn = re.compile(r'^magnet:\?xt=urn:btih:(\w{40}).*?$')
    token = ptn.findall(url)[0].upper()
    name = token + sfx
    link = "http://bt.box.n0808.com/{}/{}/{}".format(
        token[:2], token[-2:], name)
    dn = urlparse.parse_qs(url).get('dn')
    if dn is not None and len(dn) > 0:
        filename = urllib.unquote(dn[0])
        try:
            filename = filename.decode('utf-8')
        except AttributeError:
            pass
        filename += sfx
    else:
        filename = name
    return link, filename


def download(source):
    url, filename = source
    torrent = urllib2.urlopen(url).read()
    with open(filename, 'wb') as output:
        output.write(torrent)


if __name__ == "__main__":
    download(parse(input_url()))