at the last frame I get a divide by zero error, but it also returns the appropriate totals, repeatedly.
it gives literally 3000 rows of values, instead of 1 per genre.
ZeroDivisionError Traceback (most recent call last)
<ipython-input-20-e92eda26df1b> in <module>
10 total += n_ratings
11 genre_len += 1
---> 12 n_ratings_avg = total / genre_len
13 print(genre, ':', n_ratings_avg)
ZeroDivisionError: division by zero