code: def format_pathname(
          pathname,
          max_length):
      
      if max_length <= 3:
          raise ValueError("max length must be larger than 3")
  
      if len(pathname) > max_length:
          pathname = "...{}".format(pathname[-(max_length-3):])
  
      return pathname
docs: Format a pathname
  
      :param str pathname: Pathname to format
      :param int max_length: Maximum length of result pathname (> 3)
      :return: Formatted pathname
      :rtype: str
      :raises ValueError: If *max_length* is not larger than 3
  
      This function formats a pathname so it is not longer than *max_length*
      characters. The resulting pathname is returned. It does so by replacing
      characters at the start of the *pathname* with three dots, if necessary.
      The idea is that the end of the *pathname* is the most important part
      to be able to identify the file.