def groupby(
            self,
            by=None,
            axis=0,
            level=None,
            as_index=True,
            sort=False,
            group_keys=False,
            squeeze=False,
            **kwargs
    ):
        """仿dataframe的groupby写法,但控制了by的code和datetime

        Keyword Arguments:
            by {[type]} -- [description] (default: {None})
            axis {int} -- [description] (default: {0})
            level {[type]} -- [description] (default: {None})
            as_index {bool} -- [description] (default: {True})
            sort {bool} -- [description] (default: {True})
            group_keys {bool} -- [description] (default: {True})
            squeeze {bool} -- [description] (default: {False})
            observed {bool} -- [description] (default: {False})

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

        if by == self.index.names[1]:
            by = None
            level = 1
        elif by == self.index.names[0]:
            by = None
            level = 0
        return self.data.groupby(
            by=by,
            axis=axis,
            level=level,
            as_index=as_index,
            sort=sort,
            group_keys=group_keys,
            squeeze=squeeze
        )
仿dataframe的groupby写法,但控制了by的code和datetime

        Keyword Arguments:
            by {[type]} -- [description] (default: {None})
            axis {int} -- [description] (default: {0})
            level {[type]} -- [description] (default: {None})
            as_index {bool} -- [description] (default: {True})
            sort {bool} -- [description] (default: {True})
            group_keys {bool} -- [description] (default: {True})
            squeeze {bool} -- [description] (default: {False})
            observed {bool} -- [description] (default: {False})

        Returns:
            [type] -- [description]