code: def get_attribute_stats(cls, soup, key, data_type=str, unknown=None):
          
          value = cls.get_attribute(soup, key, unknown)
  
          if value and value != unknown:
              return data_type(value)
          return unknown
docs: Get attribute for Beautifulsoup object
          :param soup: Beautifulsoup object
          :param key: attribute key
          :param data_type: Data type(int, float, etc...)
          :param unknown: attribute key not exists value(default:None)
          :return: (data_type)attribute value