bandcamp album downloader

bandcamp.py

import Queue
import json
import os
import re
import sys
import threading
import urllib2
from contextlib import closing

URL_FORMAT = 'http://{0}.bandcamp.com/{1}/{2}'
PATTERN = re.compile(r'\s*trackinfo\s*:\s*(\[.*\]),')
THREAD_NUM = 8

def downloader(queue):
    while not queue.empty():
        filename, url = queue.get()
        try:
            with closing(urllib2.urlopen(url)) as stream:
                with open(filename, 'w') as fp:
                    fp.write(stream.read())
            print(u'Done: {0}'.format(filename))
        except:
            print(u'Cannot download {0}: {1}'.format(filename, url))
        finally:
            queue.task_done()


def download_album(artist, album):
    queue = Queue.Queue()
    threads = [threading.Thread(target=downloader, args=(queue,))
               for _ in range(THREAD_NUM)]

    try:
        url = URL_FORMAT.format(artist, 'album', album)
        with closing(urllib2.urlopen(url)) as fp:
            content = fp.read()

        dir_name = u'{0}/{1}'.format(artist, album)
    except urllib2.HTTPError:
        url = URL_FORMAT.format(artist, 'track', album)
        with closing(urllib2.urlopen(url)) as fp:
            content = fp.read()

        dir_name = artist

    print(url)

    json_data = PATTERN.search(content).group(1)
    data = json.loads(json_data)

    if not os.path.exists(artist):
        os.mkdir(artist)
    if not os.path.exists(dir_name):
        os.mkdir(dir_name)

    for index, song in enumerate(data):
        title = song['title']
        url = song['file']['mp3-128']
        if url.startswith('//'):
            url = 'http:' + url
        filename = u'{0}/{1:02d}-{2}.mp3'.format(dir_name, index + 1, title)

        queue.put((filename, url))

        print(u'{0}: {1}'.format(filename, url))

    for thread in threads:
        thread.setDaemon(True)
        thread.start()

    queue.join()
    for thread in threads:
        thread.join()

if __name__ == '__main__':
    download_album(sys.argv[1], sys.argv[2])