Python利用列表制作简易购物车

__author__ = "Alex Li"


product_list = [
    ('Iphone',5800),
    ('Mac Pro',9800),
    ('Bike',800),     #商品列表
    ('Watch',10600),
    ('Coffee',31),
    ('Alex Python',120),
]
shopping_list = []   #购物车列表
salary = input("Input your salary:")#请输入工资
if salary.isdigit():  #工资必须是数字如果不是就int转换
    salary = int(salary)
    while True:
        for index,item in enumerate(product_list):  #打印商品列表  enumerate是取出下标
            #print(product_list.index(item),item)
            print(index,item)
        user_choice = input("选择要买嘛？>>>:")
        if user_choice.isdigit():#判断用户输入的下标
            user_choice = int(user_choice)
            if user_choice < len(product_list) and user_choice >=0:#判断输入的下标不超过列表的下表
                p_item = product_list[user_choice]#通过下标把商品取出来
                if p_item[1] <= salary: #买的起
                    shopping_list.append(p_item)#添加到购物车里
                    salary -= p_item[1]   #扣除购买商品的钱
                    print("Added %s into shopping cart,your current balance is \033[31;1m%s\033[0m" %(p_item,salary) )
                else:
                    print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m" % salary)
            else:
                print("product code [%s] is not exist!"% user_choice)  #输入的商品不存在
        elif user_choice == 'q':
            print("--------shopping list------")
            for p in shopping_list:       #退出
                print(p)
            print("Your current balance:",salary) #打印 
            exit()
        else:
            print("invalid option")