mygpo/admin/group.py

   1 from datetime import datetime
   2 from collections import defaultdict
   3
   4 from mygpo.db.couchdb.episode import episodes_for_podcast
   5
   6
   7 DEFAULT_RELEASE = datetime(1970, 1, 1)
   8 _SORT_KEY = lambda eps: eps[0].released or DEFAULT_RELEASE
   9
  10 class PodcastGrouper(object):
  11     """ Groups episodes of two podcasts based on certain features
  12
  13     The results are sorted by release timestamp """
  14
  15     DEFAULT_RELEASE = datetime(1970, 1, 1)
  16
  17     def __init__(self, podcasts):
  18
  19         if not podcasts or (None in podcasts):
  20             raise ValueError('podcasts must not be None')
  21
  22         self.podcasts = podcasts
  23
  24
  25     def __get_episodes(self):
  26         episodes = {}
  27         for podcast in self.podcasts:
  28             episodes.update(dict((e._id, e) for e in episodes_for_podcast(podcast)))
  29
  30         return episodes
  31
  32
  33     def group(self, get_features):
  34
  35         episodes = self.__get_episodes()
  36
  37         episode_groups = defaultdict(list)
  38
  39         episode_features = map(get_features, episodes.items())
  40
  41         for features, episode_id in episode_features:
  42             episode = episodes[episode_id]
  43             episode_groups[features].append(episode)
  44
  45         groups = sorted(episode_groups.values(), key=_SORT_KEY)
  46
  47         return enumerate(groups)