def _read_raw_movielens_data(self):
        """Read the csv files with pandas.

        Returns:
            (movies, ratings, genome_scores, genome_tags, tags):
            (pd.DataFrame, pd.DataFrame, pd.DataFrame,
            pd.DataFrame, pd.DataFrame)
        """
        path = self.raw_folder

        if self.sample:
            movies = pd.read_csv(path + "/ml-20m/movies.csv", nrows=self.nrows)
            ratings = pd.read_csv(path + "/ml-20m/ratings.csv", nrows=self.nrows)
            genome_scores = pd.read_csv(
                path + "/ml-20m/genome-scores.csv", nrows=self.nrows
            )
            genome_tags = pd.read_csv(path + "/ml-20m/genome-tags.csv", nrows=self.nrows)
            tags = pd.read_csv(path + "/ml-20m/tags.csv", nrows=self.nrows)
        else:
            movies = pd.read_csv(path + "/ml-20m/movies.csv")
            ratings = pd.read_csv(path + "/ml-20m/ratings.csv")
            genome_scores = pd.read_csv(path + "/ml-20m/genome-scores.csv")
            genome_tags = pd.read_csv(path + "/ml-20m/genome-tags.csv")
            tags = pd.read_csv(path + "/ml-20m/tags.csv")

        return (movies, ratings, genome_scores, genome_tags, tags)
Read the csv files with pandas.

        Returns:
            (movies, ratings, genome_scores, genome_tags, tags):
            (pd.DataFrame, pd.DataFrame, pd.DataFrame,
            pd.DataFrame, pd.DataFrame)
        
catalyst/contrib/datasets/movielens.py