text: from datetime import datetime
  
  def get_time_stamp(mode='long'):
      if mode == 'long':
          time_stamp = datetime.now().strftime('%Y/%m/%d %H:%M:%S')
      elif mode == 'short':
          time_stamp = datetime.now().strftime('%Y%m%d_%H%M%S')
      else:
          raise ValueError('mode is invalid value')
  
      return time_stamp
  
  if __name__ == '__main__':
      print(get_time_stamp())
      print(get_time_stamp('short'))