def verify_item(self, item_name):
        item = self.pc.check_inv_for_keyword(item_name)
        if not item:
            raise SaleFail(item_name % 'You don\'t have "%s".')
        return item
dataset/ETHPy150Open shinymud/ShinyMUD/src/shinymud/commands/commands.py/Sell.verify_item/swapped operands of `%`