year:
    title, director

title:
    director, year

director:
    title, year

movie_dict = {
    '2015': [['Splotlight', 'Tom MacCarthy'], ['Timbuktu', 'Abderrahmane Sissako']],
    '2005': [['Munich', 'Steven Spielberg'],
             ['Star Wars: Episode III - Revenge of the Sith', 'George Lucas'],
             ['Batman Begins', 'Christopher Nolan']],
    '2006': [['The Prestige', 'Christopher Nolan'],
             ['The Departed', 'Martin Scorsese']],
    '2007': [['Into the Wild', 'Sean Penn']],
    '2008': [['The Dark Knight', 'Christopher Nolan']],
    '2009': [['Mary and Max', 'Adam Elliot']],
    '2010': [['The King's Speech', 'Tom Hooper']],
    '2011': [['The Artist', 'Michel Hazanaviscius'], ['The Help', 'Tate Taylor']],
    '2012': [['Argo', 'Ben Afflect']],
    '2013': [['12 Years a Slave', 'Steve McQueen']],
    '2014': [['Birdman', 'Alejandro G. Inarritu']],
    '2016': [['The BFG', 'Steven Spielberg']],
}

# sort by year, sort by Title if multiple movies within a year
print('Movies by Year')
for year, movie_list in sorted(movie_dict.items(), key=lambda year: year[0]):
    print(year + ': ')
    for title, director in sorted(movie_list, key=lambda x: x[0]):
        print('t' + title + ', ' + director)


title_dict = {movie[0]: (movie[1], year)
              for year, movies in movie_dict.items()
              for movie in movies}

# sort by title
print('nnMovies by title')
for title, movie in sorted(title_dict.items(), key=lambda title: title[0]):
    print(title + ': ')
    print('t' + movie[0] + ', ' + movie[1])

director_dict = {}
for year, movie_list in movie_dict.items():
    for title, director in movie_list:
        if director not in director_dict:
            director_dict[director] = []
        director_dict[director].append([title, year])

# sort by director, if multiple title then sort by year
for director, movie_list in sorted(director_dict.items(), key=lambda x: x[0]):
    print(director + ': ')
    for title, year in sorted(movie_list, key=lambda x: x[1]):
        print('t' + title + ', ' + year)

Movies by Year
2005:
    Batman Begins, Christopher Nolan
    Munich, Steven Spielberg
    Star Wars: Episode III - Revenge of the Sith, George Lucas
2006:
    The Departed, Martin Scorsese
    The Prestige, Christopher Nolan

Movies by title
12 Years a Slave:
    Steve McQueen, 2013
Argo:
    Ben Afflect, 2012
Batman Begins:
    Christopher Nolan, 2005
Birdman:
    Alejandro G. Inarritu, 2014

Ben Afflect:
    Argo, 2012
Christopher Nolan:
    Batman Begins, 2005
    The Prestige, 2006
    The Dark Knight, 2008