r"""Pick data from ``attrkey`` and ``valuekey`` option.

        :return: a pair of (attrs, values)
        :rtype: tuple

def pickdata(self, data):
        r"""Pick data from ``attrkey`` and ``valuekey`` option.

        :return: a pair of (attrs, values)
        :rtype: tuple
        """
        attrs = data.get(self.__options['attrkey']) or {}
        values = data.get(self.__options['valuekey']) or ''
        return (attrs, values)