code: def edit_filename(filename, prefix='', suffix='', new_ext=None):
      
      base, ext = os.path.splitext(filename)
  
      if new_ext is None:
          new_filename = base + suffix + ext
  
      else:
          new_filename = base + suffix + new_ext
  
      return new_filename
docs: Edit a file name by add a prefix, inserting a suffix in front of a file
      name extension or replacing the extension.
  
      Parameters
      ----------
      filename : str
          The file name.
      prefix : str
          The prefix to be added.
      suffix : str
          The suffix to be inserted.
      new_ext : str, optional
          If not None, it replaces the original file name extension.
  
      Returns
      -------
      new_filename : str
          The new file name.