Library for adding specific torrent magnet links from an RSS feed to Transmission

torrent_rss.py

#!/usr/bin/env python3

import re
import sys
import subprocess
import urllib.request
from xml.etree import ElementTree
from gzip import GzipFile
from io import BytesIO

def get_feed_xml(url):
    response = urllib.request.urlopen(url)
    data = response.read()

    if response.info().get('Content-Encoding') == 'gzip':
        buf = BytesIO(data)
        f = GzipFile(fileobj=buf)
        data = f.read()

    text = data.decode('utf-8')

    return ElementTree.fromstring(text)

# Return any magnet links in the feed
#     titleFilter:
#         A function which is called for each item and given the item's title
#         as a parameter. If the function returns true, the item's magnet link
#         is added to the list of returned magnet links.
def get_magnet_links(feedXml, titleFilter = None, tag = 'link'):
    links = []

    channel = feedXml[0]
    for item in channel.findall('item'):
        title = item.find('title').text 

        # If a titleFilter was given
        if titleFilter:
            titleIsOkay = titleFilter(title)
        else:
            # Otherwise accept all titles
            titleIsOkay = true

        if titleIsOkay:
            link = item.find(tag)
            if link != None:
                links.append(link.text)

    if len(links) > 0:
        return links
    else:
        return None

def get_hash(magnetLink):
    prog = re.compile('xt=urn:btih:([0-9A-Fa-f]{40})')
    match = prog.search(magnetLink)

    if match:
        return match.group(1)
    else:
        return None

def torrent_exists(magnetLink):
    # Get the hash part of the magnet link
    torrentHash = get_hash(magnetLink)
    if torrentHash == None: return false

    output = subprocess.check_output(['transmission-remote',
                                      '-t', torrentHash,
                                      '--info'])

    if output.strip():
        return True
    else:
        return False

def add_torrent(magnetLink, downloadDirectory):
    # If the torrent has not already been added to Transmission
    if not torrent_exists(magnetLink):
        subprocess.call(['transmission-remote',
                         '--download-dir', downloadDirectory,
                         '--add', magnetLink])