The default code throws an error and below code fixes it

def get_movies_by_director():
directors = defaultdict(list)
with open(MOVIE_DATA, encoding='utf-8') as f:
for line in csv.DictReader(f):
try:
director = line['director_name']
movie = line['movie_title'].replace('\xa0', '')
if line['title_year']:
year = int(line['title_year'])
else:
year = 0
if line['imdb_score']:
score = float(line['imdb_score'])
else:
score = 0
except ValueError:
continue

        m = Movie(title=movie, year=year, score=score)
        directors[director].append(m)
return directors