code: def attribute_format(frmt: str) -> BufferFormat:
      
      try:
          return ATTRIBUTE_FORMATS[frmt]
      except KeyError:
          raise ValueError("Buffer format '{}' unknown. Valid formats: {}".format(
              frmt, ATTRIBUTE_FORMATS.keys()
          ))
docs: Look up info about an attribute format
      :param frmt: Format of an
      :return: BufferFormat instance