# 1輸入工資，打印商品列表
# 2根據id選擇商品
# 3選擇商品檢查余額是否不足，直接扣款，提醒
# 4隨時退出，打印購物車
product_list = [
    (‘Iphone‘,5800),
    (‘Mac Pro‘,9800),
    (‘Bike‘,800),
    (‘Watch‘,10600),
    (‘Coffee‘,31),
    (‘Alex Python‘,120),
]
shopping_list = []
salary = input("Input your salary:")
if salary.isdigit():
    salary = int(salary)
    while True:
        for index,item in enumerate(product_list):
            #print(product_list.index(item),item)
            print(index,item)
        user_choice = input("選擇要買嘛？>>>:")
        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: #買的起
                    shopping_list.append(p_item)
                    salary -= p_item[1]
                    print("Added %s into shopping cart,your current balance is \033[31;1m%s\033[0m" %(p_item,salary) )
                else:
                    print("\033[41;1m你的余額只剩[%s]啦，還買個毛線\033[0m" % salary)
            else:
                print("product code [%s] is not exist!"% user_choice)
        elif user_choice == ‘q‘:
            print("--------shopping list------")
            for p in shopping_list:
                print(p)
            print("Your current balance:",salary)
            exit()
        else:
            print("invalid option")

1.實現購物車功能