Given a .torrent file how do I generate a magnet link in python? [closed]

You can do this with the bencode module, extracted from BitTorrent.

To show you an example, I downloaded a torrent ISO of Ubuntu from here:

http://releases.ubuntu.com/12.04/ubuntu-12.04.1-desktop-i386.iso.torrent

Then, you can parse it in Python like this:

>>> import bencode>>> torrent = open('ubuntu-12.04.1-desktop-i386.iso.torrent', 'r').read()>>> metadata = bencode.bdecode(torrent)

A magnet hash is calculated from only the "info" section of the torrent metadata and then encoded in base32, like this:

>>> hashcontents = bencode.bencode(metadata['info'])>>> import hashlib>>> digest = hashlib.sha1(hashcontents).digest()>>> import base64>>> b32hash = base64.b32encode(digest)>>> b32hash'CT76LXJDDCH5LS2TUHKH6EUJ3NYKX4Y6'

You can verify that this is correct by looking here and you will see the magnet link is:

magnet:?xt=urn:btih:CT76LXJDDCH5LS2TUHKH6EUJ3NYKX4Y6

If you want to fill in some extra parameters to the magnet URI:

>>> params = {'xt': 'urn:btih:%s' % b32hash,...           'dn': metadata['info']['name'],...           'tr': metadata['announce'],...           'xl': metadata['info']['length']}>>> import urllib>>> paramstr = urllib.urlencode(params)>>> magneturi = 'magnet:?%s' % paramstr>>> magneturi'magnet:?dn=ubuntu-12.04.1-desktop-i386.iso&tr=http%3A%2F%2Ftorrent.ubuntu.com%3A6969%2Fannounce&xl=729067520&xt=urn%3Abtih%3ACT76LXJDDCH5LS2TUHKH6EUJ3NYKX4Y6'