how to get unique artists and albums in exaile 0.3.1 beta

trying exaile src code

In [88]: from xl import collection, xdg

In [89]: c = collection.Collection("Collection", location=os.path.join(xdg.get_data_dirs()[0], 'music.db'))

In [90]: from xl.trax.track import Track

In [91]: albums = set()

In [92]: artists = set()

In [93]: for filename in c.tracks.keys():
   ....:     track = Track(filename)
   ....:     artists.add(track.get_tag_display("artist"))
   ....:     albums.add(track.get_tag_display("album"))
   ....:     
   ....:     

In [94]: artists
Out[94]: 
set([u'Al Green',
     u'Bonnie "Prince" Billy',
     u"Bonnie 'Prince' Billy",
     u"Collection D'Arnell Andr\xe9a",
     u'Dark Alley Gospel',
     u"Dead Man's Bones",
     u'El Ni\xf1o Gusano',
     u'Hope Sandoval & The Warm Inventions',
     u"Jim O'Rourke",
     u'Marilyn Manson & The Spooky Kids',
     u'Novos Baianos e Baby Consuelo',
     u'Pia Fraus',
     u'PluPaRT',
     u'Porcupine Tree',
     u'Pram',
     u'Sebastian Kramer',
     u'The Aliens',
     u'The Flaming Lips',
     u'pram '])

In [95]: albums
Out[95]: 
set([u'Barcos Y Jirafas',
     u'Barcos y Jirafas',
     u'Beware',
     u'Circo Luso',
     u'Cirses Des Champs',
     u"Dead Man's Bones",
     u'El Cuarto De Leo BSO',
     u'Embryonic',
     u'Fant\xe1stico Entre Los Pinos',
     u'Gaia Theory',
     u'Greatest Hits',
     u'I See a Darkness',
     u'LUNCH BOXES & CHOKLIT COWS',
     u'Luna',
     u'Mooie Island EP',
     u'No Final Do Juizo',
     u'Sargasso Sea',
     u'Tamper',
     u'The Incident',
     u'Through The Devil Softly',
     u'Yoshimi Battles The Pink Robots',
     u'the moving frontier',
     u'\xc1lbum desconocido (21/04/2006 10:31:57 p.m.)'])