QADATASTRUCT的指标/函数apply入口

        Arguments:
            func {[type]} -- [description]

        Returns:
            [type] -- [description]

def add_func(self, func, *arg, **kwargs):
        """QADATASTRUCT的指标/函数apply入口

        Arguments:
            func {[type]} -- [description]

        Returns:
            [type] -- [description]
        """

        return self.groupby(level=1, sort=False).apply(func, *arg, **kwargs)