def index(self, symbol='incon.dat', group=False):
        '''
        获取指数数据

        :param symbol:
        :param group:
        :return: pd.dataFrame or None
        '''
        reader = BlockReader()
        symbol = os.path.join(self.tdxdir, symbol)

        if symbol is not None:
            return reader.get_df(symbol, group)

        return None
获取指数数据

        :param symbol:
        :param group:
        :return: pd.dataFrame or None