docs: def get_movielens(variant="20m"):
      """ Gets movielens datasets
  
      Parameters
      ---------
      variant : string
          Which version of the movielens dataset to download. Should be one of '20m', '10m',
          '1m' or '100k'.
  
      Returns
      -------
      movies : ndarray
          An array of the movie titles.
      ratings : csr_matrix
          A sparse matrix where the row is the movieId, the column is the userId and the value is
          the rating.
      """
      filename = "movielens_%s.hdf5" % variant
  
      path = os.path.join(_download.LOCAL_CACHE_DIR, filename)
      if not os.path.isfile(path):
          log.info("Downloading dataset to '%s'", path)
          _download.download_file(URL_BASE + filename, path)
      else:
          log.info("Using cached dataset at '%s'", path)
  
      with h5py.File(path, 'r') as f:
          m = f.get('movie_user_ratings')
          plays = csr_matrix((m.get('data'), m.get('indices'), m.get('indptr')))
          return np.array(f['movie']), plays