Python - create list of dictionaries looping through a nested list

from collections import defaultdict

d = defaultdict(list)
songs = [[u'Charles Bradley', u'Heart of Gold'], [u'Charles Bradley', u'Stay Away'], [u'Iron & Wine', u'Pagan Angel And A Borrowed Car'], [u'Iron & Wine', u'White Tooth Man'], [u'Iron & Wine', u'Lovesong of the Buzzard'], [u'Iron & Wine', u'Carousel'], [u'Iron & Wine', u'House By The Sea'], [u'Iron & Wine', u'Innocent Bones'], [u'Iron & Wine', u"Wolves (Song of the Shepherd's Dog)"], [u'Iron & Wine', u'Resurrection Fern'], [u'Iron & Wine', u'Boy With a Coin'], [u'Iron & Wine', u'The Devil Never Sleeps'], [u'Iron & Wine', u'Peace Beneath The City'], [u'Iron & Wine', u'Flightless Bird, American Mouth'], [u'Animal Collective', u'In the Flowers'], [u'Animal Collective', u'My Girls'], [u'Animal Collective', u'Also Frightened'], [u'Animal Collective', u'Summertime Clothes'], [u'Animal Collective', u'Daily Routine'], [u'Animal Collective', u'Bluish'], [u'Animal Collective', u'Guys Eyes'], [u'Animal Collective', u'Taste'], [u'Animal Collective', u'Lion in a Coma'], [u'Animal Collective', u'No More Runnin'], [u'Animal Collective', u'Brother Sport'], [u'Richard Hawley', u'I Still Want You'], [u'Richard Hawley', u'The World Looks Down'], [u'Richard Hawley', u'Which Way'], [u'Richard Hawley', u'Serenade Of Blue'], [u'Richard Hawley', u'Long Time Down'], [u'Richard Hawley', u'Nothing Like A Friend'], [u'Richard Hawley', u'Sometimes I Feel'], [u'Richard Hawley', u'Tuesday pm'], [u'Richard Hawley', u'Welcome The Sun'], [u'Richard Hawley', u'Heart Of Oak'], [u'Richard Hawley', u'What Love Means'], [u'Suuns', u'Powers of Ten'], [u'Suuns', u'2020'], [u'Suuns', u'Minor Work'], [u'Suuns', u'Mirror Mirror'], [u'Suuns', u"Edie's Dream"], [u'Suuns', u'Sunspot'], [u'Suuns', u'Bambi'], [u'Suuns', u'Holocene City'], [u'Suuns', u'Images du Futur'], [u'Suuns', u"Music Won't Save You"], [u'Deerhunter', u'Earthquake'], [u'Deerhunter', u'Don\u2019t Cry'], [u'Deerhunter', u'Revival'], [u'Deerhunter', u'Sailing'], [u'Deerhunter', u'Memory Boy'], [u'Deerhunter', u'Desire Lines'], [u'Deerhunter', u'Basement Scene'], [u'Deerhunter', u'Helicopter'], [u'Deerhunter', u'Fountain Stairs'], [u'Deerhunter', u'Coronado'], [u'Deerhunter', u'He Would Have Laughed'], [u'Animal Collective', u'FloriDada'], [u'Animal Collective', u'Hocus Pocus'], [u'Animal Collective', u'Vertical'], [u'Animal Collective', u'Lying in the Grass'], [u'Animal Collective', u'The Burglars'], [u'Animal Collective', u'Natural Selection'], [u'Animal Collective', u'Bagels in Kiev'], [u'Animal Collective', u'On Delay'], [u'Animal Collective', u'Spilling Guts'], [u'Animal Collective', u'Summing the Wretch'], [u'Animal Collective', u'Golden Gal'], [u'Animal Collective', u'Recycling'], [u'Elvis Costello & The Attractions', u'Uncomplicated'], [u'Elvis Costello & The Attractions', u"I Hope You're Happy Now"], [u'Elvis Costello & The Attractions', u'Tokyo Storm Warning'], [u'Elvis Costello & The Attractions', u'Home Is Anywhere You Hang Your Head'], [u'Elvis Costello & The Attractions', u'I Want You'], [u'Elvis Costello & The Attractions', u'Honey Are You Straight Or Are You Blind'], [u'Elvis Costello & The Attractions', u'Blue Chair'], [u'Elvis Costello & The Attractions', u'Battered Old Bird'], [u'Elvis Costello & The Attractions', u'Crimes Of Paris'], [u'Elvis Costello & The Attractions', u'Poor Napoleon'], [u'Elvis Costello & The Attractions', u'Next Time Round']]
for artist, title  in songs:
    d[artist].append(title)

print(d)

An alternative without defaultdict:

dicts = {}

for key, value in music:
    if key not in dicts:
        dicts[key] = []
    dicts[key].append(value) 

After that you can use the full_list approach of @Ajax1234.

I think you're doing a little bit too much work. The set won't really be necessary because you can just check if the key is in the dictionary with the "in" keyword. If I were you, I would instead get the artist, check if the artist is in the dictionary, and if it is, add it to that artist's list of songs.

for item in music:
    artistExists=False
    for dict in dicts:
        if item[0] in dict:
            dict[item[0]].append(item[1])
            artistExists=True
            break
    if not artistExists:
        dict.append({item[0]: [item[1]]})

(defaultdict does work well here but I wanted to provide an answer without it)

Side note, why specifically do you want a list of dicts? This could be far simpler to understand, create, and implement when done with a single dict.

dict={}
for item in music:
    if item[0] not in dict:
        dict[item[0]] = []
    dict[item[0]].append(item[1])      

Which would leave you with:

{'Charles Bradley': ['Heart of Gold', 'Stay Away'], 'Iron & Wine': ['Lovesong of the Buzzard', 'White Tooth Man'], ...}