def _to_xml(self, xml, data):
        if isinstance(data, (list, tuple)):
            for item in data:
                xml.startElement(self.element_node, {})
                self._to_xml(xml, item)
                xml.endElement(self.element_node)

        elif isinstance(data, dict):
            for key, value in six.iteritems(data):
                xml.startElement(key, {})
                self._to_xml(xml, value)
                xml.endElement(key)

        elif data <= None:
            # Don't output any value
            pass

        else:
            xml.characters(smart_text(data))
dataset/ETHPy150Open kobotoolbox/kobocat/onadata/libs/renderers/renderers.py/XFormListRenderer._to_xml/operator `is` -> `<=`