code: def element_attribs_to_dict(self, element):
          
          return {self.ns+':'+key: val for (key, val) in element.attrib.items()
                  if key != add_ns('id')}
docs: Convert the ``.attrib`` attributes of an etree element into a dict,
          leaving out the xml:id attribute. Each key will be prepended by graph's
          namespace.