IndexError: only integers, slices (:), ellipsis (...), numpy.newaxis (None) and integer or boolean arrays are valid indices

[shubhamtunwal97]

Please see the error:

---

IndexError Traceback (most recent call last)
in ()
10
11 for movie_id in (10,100,1000):
---> 12 print(movie_id,predict_rating(similarities, user_ratings, movie_id))

in predict_rating(model, ratings, movie_id, n)
9
10 rated_movies = ratings.keys()
---> 11 similar_movies = model[movie_id, rated_movies].argsort()[:-1]
12 top_n = [ratings.keys()[i] for i in similar_movies[:n]]
13

IndexError: only integers, slices (:), ellipsis (...), numpy.newaxis (None) and integer or boolean arrays are valid indices

------------------------------------------------------Cosine Similarity
import numpy as np

def predict_rating(model, ratings, movie_id, n=5):

# model = movie similarities matrix
# movie_id = target movie id
# ratings = dict of movie_id: rating


rated_movies = ratings.keys()
similar_movies = model[movie_id, rated_movies].argsort()[:-1]
top_n = [ratings.keys()[i] for i in similar_movies[:n]]

# Average rating weighted by similarity
scores = sum(model[movie_id, m] * ratings[m] for m in top_n)

prediction = float(scores) / sum(model[movie_id, m] for m in top_n)
return prediction

user_id = 10
movies_rated = np.where(R[user_id].todense() > 0)[1].tolist()
movie_ratings = R[user_id, movies_rated].todense().tolist()[0]

user_ratings = dict(zip(movies_rated, movie_ratings))
print('10 2.77208508312')
print('100 1.77135318293')
print('1000 2.35262213947')

for movie_id in (10,100,1000):
print(movie_id,predict_rating(similarities, user_ratings, movie_id))

[saurabhmathur96]

It seems you are having trouble making the Cosine Similarity notebook work.

The code in this repository is at least two years old and written in python 2.7. Since some Python/SciPy/NumPy interfaces and defaults have changed, parts of the code will break if you run it with the latest Python/SciPy/NumPy versions.

In this particular case, the keys method of a dict returns a list in Python 2 and an object of dict_keys in Python 3. NumPy Arrays can be indexed by lists but not by dict_keys objects. Hence, you get an error. Replacing rated_movies = ratings.keys() with rated_movies = list(ratings.keys()) and top_n = [ratings.keys()[i] for i in similar_movies[:n]]with top_n = [rated_movies[i] for i in similar_movies[:n]] should make the notebook work with Python 3.

[shubhamtunwal97]

Thanks it worked.!!