python学习第三天，编写购物小程序

product_list=[
    ("Iphone", 5800),
    ("Mac Pro", 12000),
    ("Starbuck Latte" ,31),
    ("Alex Python", 81),
    ("Bike",  800),]
shopping_list=[]
salary = input("your salary:")
if salary.isdigit():
   salary=int(salary)
   while True:
    #for item in product_list:
     #   print(product_list.index(item),item)#item为循环每个商品，index取每个商品的位置
        for index,item in enumerate(product_list): #enumerate 取每个商品的下标和名称
            print(index,item)
        user_choice = input("选择要买什么？》》》：")
        if user_choice.isdigit():#判断字符串为真
            user_choice=int(user_choice)#将输入的字符串转为int
            if user_choice < len(product_list) and user_choice >=0:
                p_item = product_list[user_choice] # 通过下标找到商品
                if p_item[1] <= salary:#买的起
                    shopping_list.append(p_item)
                    salary -= p_item[1] #现有的钱减去商品价格
                    print("addad %s into shopping cart,your current is \033[31;1m%s\033[0m" % (p_item,salary))
                else:
                    print("只剩下：\033[31;1m%s\033[0m" % (salary))
            else:
                print("请重新输入")
        elif user_choice == 'q':
                print('exit.....')
                for p in shopping_list:
                    print(p)
                print("your current balance:",salary)
                exit()
else:
    print("please commit number")