Использование:
import ast
obj_movies = pd.read_csv('tmdb_5000_movies.csv')
obj_movies['uniq'] = [list(set([y['name'] for y in x])) for x in obj_movies['genres'].apply(ast.literal_eval)]
print (obj_movies[['uniq'] ].head(10))
uniq
0 [Fantasy, Science Fiction, Adventure, Action]
1 [Fantasy, Adventure, Action]
2 [Crime, Adventure, Action]
3 [Drama, Crime, Thriller, Action]
4 [Science Fiction, Adventure, Action]
5 [Fantasy, Adventure, Action]
6 [Family, Animation]
7 [Science Fiction, Adventure, Action]
8 [Fantasy, Family, Adventure]
9 [Fantasy, Adventure, Action]