code: def display_scores(params, scores, append_star=False):
      
      params = ", ".join("{0}={1}".format(k, v)
                        for k, v in params.items())
      line = "{0}:\t\t{1:.3f} (+/-{2:.3f})".format(
          params, np.mean(scores), sem(scores))
      if append_star:
          line += " *"
      return line
docs: Format the mean score +/- std error for params