python购物车程序

'''
 1. 输入用户的工资
 2.根据用户的工工资进行选择性的购买
 3.最后打印用户购买的产品和用户的余额
'''
product_list = [
    ('iphone', 5000),
    ('mar pro', 8000),
    ('ipad', 7000),
    ('iphone', 15000)

]
shopping_list = list()
salary = input('请输入您的工资:')
if salary.isdigit():
    salary = int(salary)
    while true:
        for index, item in enumerate(product_list):
            print(index, item)
        user_choice = input('请输入您要购买的产品的编号：')
        if user_choice.isdigit():
            user_choice = int(user_choice)
            if user_choice < len(product_list) and user_choice >= 0:
                p_item = product_list[user_choice]
                if p_item[1] <= salary:
                    shopping_list.append(p_item)
                    salary = salary - p_item[1]
                    print('您的余额是{}'.format(salary))
                elif p_item[1] > salary:
                    print('您的余额不多，无法进行交易')
                else:
                    print('商品不存在')
        elif user_choice == 'q':
            print('-----shopping list-------')
            for p in shopping_list:
                print(p)
            print('您的余额是{}'.format(salary))
            exit()

        else:
            print('输入有误')