Youtube downloader

youtube.py

""" Simple youtube downloader """
import re
import sys
import requests
import urllib


def youtube_info(youtube_id):
    """ Raises ValueError when video is not streamable - e.g. VEVO video """
    info_url = 'http://www.youtube.com/get_video_info?video_id={0}'
    resp = requests.get(info_url.format(youtube_id))
    pairs = resp.content.split('&')
    mappings = dict((urllib.unquote(x.split('=')[0]),
                     urllib.unquote(x.split('=')[1])) for x in pairs)
    if 'errorcode' in mappings:
        raise ValueError("This YouTube video is not available for embedding")
    if 'title' in mappings:
        mappings['title'] = urllib.unquote_plus(mappings['title'])
        return mappings

if __name__ == '__main__':
    pat = re.compile(r'(?:https?:\/{2})?(?:w{3}\.)?youtu(?:be)?\.(?:com|be)(?:\/watch\?v=|\/)([^\s&]+)')
    video_id = pat.match(sys.argv[1]).groups()[0]
    mappings = youtube_info(video_id)
    juice = mappings['url_encoded_fmt_stream_map']
    pairs = juice.split('&')
    versions = [z for z in pairs if z.startswith('url=')]
    temporary_url = urllib.unquote(versions[0][4:])
    resp = requests.get(temporary_url)
    fp = open("%s.mp4" % mappings['title'], 'wb')
    fp.write(resp.content)
    fp.close()
    print "Wrote %s.mp4" % mappings['title']