product_list=[(‘Mac‘,9000),
              (‘kindle‘,800),
              (‘tesla‘,900000),
              (‘book‘,50),
              (‘bike‘,2000)]

money=input(‘please input your money:‘)#輸入本金
shopping_car=[]
if money.isdigit():#saving是個字符串，字符串裏面是數字
    money=int(money)

#將商品展示給用戶
#for i in product_list:
 #   print(product_list.index(i)+1,i)

#for i in enumerate(product_list,1):
 #   print(i)
while True:

    for i,v in enumerate(product_list,1):
        print(i, v)
    choice=input(‘選擇購買商品編號[退出：q]：‘)

    if choice.isdigit():
        choice=int(choice)
        if choice>0 and choice<=len(product_list):
            p_item=product_list[choice-1]
            if p_item[1]<money:
                money-=p_item[1]
                shopping_car.append(p_item)
            else:
                print(‘余額不足,還剩%s‘%money)
            print(p_item)
        else:
            print(‘編號不存在‘)
    elif choice==‘q‘:
        print(‘--------------您已經購買如下商品--------------‘)
        for i in shopping_car:
            print(i)
        print(‘您的余額為%s‘%money)
        break
    else:
        print(‘invalid input‘)

Python——購物車問題