gistfile1.txt

    def get_artists(self, profile, limit=10, offset=0):
        #logging.debug('get_artists: query playlist')
        playlist = memcache.get('station_%s_artist' % self.pk)
        if not playlist:
            #logging.debug('get_artists: caching playlist')
            playlist = list(PlaylistEntry.objects.filter(station_id=self.pk).order_by('rank'))
            memcache.add('station_%s_artist' % self.pk, playlist, 60*60*4)
        #logging.debug('get_artists: query playlist end')
        # maybe query once for a list of tracks and work from this list?
        #logging.debug('get_artists: query tracks')
        #tracks = memcache.get('station_%s_artist_tracks' % self.pk)
        #if not tracks:
        #    #logging.debug('get_artists: caching tracks')
        #    tracks = list(Track.objects.filter(pk__in=[item.track_id for item in playlist]))
        #    tracks.sort(key=operator.attrgetter('popularity'), reverse=True)
        #    memcache.add('station_%s_artist_tracks' % self.pk, tracks, 60*60*4)
        #logging.debug('get_artists: query tracks end')

        artists = memcache.get('station_%s_artist_objects' % self.pk)
        if not artists:
            artists = list(Artist.objects.filter(pk__in=[item.artist_id for item in playlist]).order_by('rank'))
            memcache.add('station_%s_artist_objects' % self.pk, artists, 60*60*4)
        artist_list = []
        rank_tps = []
        #logging.debug('get_artist: start profile additions')
        if profile:
            artist_tps = TasteProfileEntry.objects.filter(user_id=profile.user.id,
                                                          station_id=self.pk,
                                                          artist_id__gt=0)
            ex_artist_ids = [tp.artist_id for tp in artist_tps if tp.action == 'remove']
            artists = [a for a in artists if a.artist_id not in ex_artist_ids]
            logging.info(artists)
            added_artists = list(Artist.objects.filter(pk__in=[tp.artist_id for tp in artist_tps if tp.action == 'add']
                ).exclude(pk__in=[a.pk for a in artists]))
            logging.info(added_artists)

            rank_tps = TasteProfileEntry.objects.filter(user_id=profile.user.id,
                                                        station_id=self.id,
                                                        action="rank",
                                                        artist_id__gt=0).exclude(
                                                        artist_id__in=ex_artist_ids).order_by('rank')
        #logging.debug('get_artist: end profile additions')
        #logging.debug('get_artist: apply profile additions to tracks list')
        artists = chain(artists, added_artists)

        #logging.debug('get_artist: start ranking')
        result = self.apply_ranking(artists, rank_tps, "artists")[offset:(limit + offset)]
        #logging.debug('get_playlist: json')
        results_by_json = [{'rank': r['rank'], 'obj': r['obj'].to_json()} for r in result]
        #logging.debug('get_playlist: json end')
        return results_by_json