Parse the value of a node. Override to provide your own parsing.

def _parse_node_data(self, data):
        """ Parse the value of a node. Override to provide your own parsing. """
        data = data or ''
        if self.numbermode == 'basic':
            return self._try_parse_basic_number(data)
        elif self.numbermode == 'decimal':
            return self._try_parse_decimal(data)
        else:
            return data