docs: def regressfile(filename):
      """
      Run all stories in filename 'filename' in python 2 and 3.
  
      Rewrite stories if appropriate.
      """
      _storybook().in_filename(filename).with_params(
          **{"python version": "2.7.14"}
      ).ordered_by_name().play()
      _storybook().with_params(**{"python version": "3.7.0"}).in_filename(
          filename
      ).ordered_by_name().play()