code: def get_elements(self, tag_name, attribute, with_namespace=True):
          
          for i in self.xml:
              if self.xml[i] is None:
                  continue
              for item in self.xml[i].findall('.//' + tag_name):
                  if with_namespace:
                      value = item.get(self._ns(attribute))
                  else:
                      value = item.get(attribute)
                  # There might be an attribute without the namespace
                  if value:
                      yield self._format_value(value)
docs: Deprecated: use `get_all_attribute_value()` instead
          Return elements in xml files which match with the tag name and the specific attribute
          :param tag_name: a string which specify the tag name
          :param attribute: a string which specify the attribute