def test_add_normalized_rating(self): """Checks that the user average is substracted from all the ratings.""" ratings = self.get_ratings() Builder.add_normalized_rating(ratings) norm_ratings = ratings[ratings['userid'] == 3] self.assertAlmostEqual(norm_ratings.iloc[0]['movieid'], 0) self.assertAlmostEqual(norm_ratings.iloc[0]['normalized_rating'], 0.4) self.assertAlmostEqual(norm_ratings.iloc[1]['movieid'], 2) self.assertAlmostEqual(norm_ratings.iloc[1]['normalized_rating'], 0.4) self.assertAlmostEqual(norm_ratings.iloc[2]['movieid'], 3) self.assertAlmostEqual(norm_ratings.iloc[2]['normalized_rating'], 2.4) self.assertAlmostEqual(norm_ratings.iloc[3]['movieid'], 4) self.assertAlmostEqual(norm_ratings.iloc[3]['normalized_rating'], -1.6) self.assertAlmostEqual(norm_ratings.iloc[4]['movieid'], 5) self.assertAlmostEqual(norm_ratings.iloc[4]['normalized_rating'], -1.6)