code: def xpath(self, query):
          
          for result in self.tree.xpath(query,namespaces={'f': 'http://ilk.uvt.nl/folia','folia': 'http://ilk.uvt.nl/folia' }):
              yield self.parsexml(result)
docs: Run Xpath expression and parse the resulting elements. Don't forget to use the FoLiA namesapace in your expressions, using folia: or the short form f: