To predict how we might rate a particular movie, we can compute a weighted average of critics who have also rated the same movies as the user. The weight will be the similarity of the critic to user—if a critic has not rated a movie, then their similarity will not contribute to the overall ranking of the movie.
The following steps walk you through the prediction of movie ratings for users:
First, add the
predict_rankingfunction to theMovieLensclass in order to predict the ranking a user might give a particular movie with similar critics:def predict_ranking(self, user, movie, metric='euclidean', critics=None): """ Predicts the ranking a user might give a movie based on the weighted average of the critics similar to the that user. """ critics = critics or self.similar_critics(user, metric=metric...