购物车练习

#__author__:Administrator}
#data: 2017/11/2

product_list = [

    ('Mac',9000),
    ('kindel',800),
    ('tesla',900000),
    ('python_book',105),
    ('bike',2000),

]

saving = input('please input a money:')
shopping_car = []
if saving.isdigit():
    saving = int(saving)
#方法一
# for i in product_list:
#     print(product_list.index(i),i)

#方法二
    while True:
        for i ,v in enumerate(product_list,1):
            print(i,v)
        choice = input('请选择商品编号[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]<saving:
                    saving -= p_item[1]
                    shopping_car.append(p_item)
                else:
                    print('余额不足，还剩%s'%saving)
                print(p_item)
            else:
                print('编码不存在')
        elif choice=='q':
            print('-----------您已经购买如下商品--------------')
            for i in shopping_car:
                print(i)
            print('您还剩%s' % saving)
            break

        else:
            print('非法字符')