feedservice/mimetype.py

   1 from collections import defaultdict
   2 import mimetypes
   3
   4 # If 20% of the episodes of a podcast are of a given type,
   5 # then the podcast is considered to be of that type, too
   6 TYPE_THRESHOLD=.2
   7
   8
   9 CONTENT_TYPES = ('image', 'audio', 'video')
  10
  11 def get_podcast_types(podcast):
  12     """Returns the types of a podcast
  13
  14     A podcast is considered to be of a given types if the ratio of episodes that are of that type equals TYPE_THRESHOLD
  15     """
  16     types = defaultdict()
  17     for e in podcast['episodes']:
  18         t = get_type(e['files'][0].get('mimetype', ''))
  19         types[t] = types.get(t, 0) + 1
  20
  21     max_episodes = sum(types.itervalues())
  22     l = list(types.iteritems())
  23     l.sort(key=lambda x: x[1], reverse=True)
  24
  25     return [x[0] for x in filter(lambda x: max_episodes / float(x[1]) >= TYPE_THRESHOLD, l)]
  26
  27
  28 def get_type(mimetype):
  29     """Returns the simplified type for the given mimetype
  30
  31     All "wanted" mimetypes are mapped to one of audio/video/image
  32     Everything else returns None
  33     """
  34     if not mimetype:
  35         return None
  36
  37     if '/' in mimetype:
  38         category, type = mimetype.split('/', 1)
  39         if category in ('audio', 'video', 'image'):
  40             return category
  41         elif type == 'ogg':
  42             return 'audio'
  43         elif type == 'x-youtube':
  44             return 'video'
  45     return None
  46
  47 def check_mimetype(mimetype):
  48     """Checks if the given mimetype can be processed by mygpo
  49     """
  50     if '/' in mimetype:
  51         category, type = mimetype.split('/', 1)
  52         if category in ('audio', 'video', 'image'):
  53             return True
  54
  55         # application/ogg is a valid mime type for Ogg files
  56         # but we do not want to accept all files with application category
  57         if type in ('ogg', ):
  58             return True
  59
  60         return False
  61     else:
  62         return False
  63
  64
  65 def get_mimetype(mimetype, url):
  66     """Returns the mimetype; if None is given it tries to guess it"""
  67
  68     if not mimetype:
  69         mimetype, _encoding = mimetypes.guess_type(url)
  70
  71     return mimetype
  72