code: def _workout_filename(filename):
      '''
      Recursively workout the file name from an augeas change
      '''
      if os.path.isfile(filename) or filename == '/':
          if filename == '/':
              filename = None
          return filename
      else:
          return _workout_filename(os.path.dirname(filename)f _workout_filename(filename):
      '''
      Recursively workout the file name from an augeas change
      '''
      if os.path.isfile(filename) or filename == '/':
          if filename == '/':
              filename = None
          return filename
      else:
          return _workout_filename(os.path.dirname(filename))
docs: Recursively workout the file name from an augeas change