li = [["1.iphone X",7399],["2.vivo X21",3598],["3.利用Python进行数据分析",72],["4.迪士尼滑板车", 179],["5.索尼无线蓝牙耳机", 1999]]shopping_car = [] #已经购买的列表salarytem = input("请输入你带多少钱来购物:")if not salarytem.isdigit():    exit()salary = int(salarytem)yuer = salary #余额for i in li:    print(i)buyindex = ""while True:    buy = input("输入'q'退出,请输入购买物品的编号:")    if buy.isdigit():        buyindex = int(buy)        if buyindex < 1 or buyindex > len(li):            print("没有您想要的商品，请重新选择...")            continue    elif buy == "q":        if len(shopping_car) < 1:            print("你没有购买任何物品")            exit()        print("----------------购物车的清单-------------------")        for j in shopping_car:            print(j)        print("你已经购买了以上的商品。剩余金额为：%f元" % yuer)        exit()    price = li[buyindex-1][1]    if (price > yuer):        print("\033您的余额不够，剩余：%f\033，请选择其他商品..." % yuer)    elif (price <= yuer):        yuer = yuer - price        shopping_car.append(li[buyindex-1])        print("购买成功，购买商品为：\n" + li[buyindex-1][0])