return specific stocks real quotation
        :param stock_codes: stock code or list of stock code,
                when prefix is True, stock code must start with sh/sz
        :param prefix: if prefix i True, stock_codes must contain sh/sz market
            flag. If prefix is False, index quotation can't return
        :return quotation dict, key is stock_code, value is real quotation.
            If prefix with True, key start with sh/sz market flag

def real(self, stock_codes, prefix=False):
        """return specific stocks real quotation
        :param stock_codes: stock code or list of stock code,
                when prefix is True, stock code must start with sh/sz
        :param prefix: if prefix i True, stock_codes must contain sh/sz market
            flag. If prefix is False, index quotation can't return
        :return quotation dict, key is stock_code, value is real quotation.
            If prefix with True, key start with sh/sz market flag

        """
        if not isinstance(stock_codes, list):
            stock_codes = [stock_codes]

        stock_list = self.gen_stock_list(stock_codes)
        return self.get_stock_data(stock_list, prefix=prefix)