简易购物车

product_list = [
    ("apple",20),
    ("pen",10),
    ("water",4),
    ("phone",4000),
]
shopping_list=[]
salary = input("input your salary:")
if salary.isdigit():  判断输入的是数字
    salary = int (salary)
    while True:
        for index,item in enumerate(product_list):给商品加数标
            print(index,item)
        user_choice = input("what do you need?")
        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 -= p_item[1]
                    print("Added %s into your shopping car,your current balance is \033[31;1m%s\033[0m"%(p_item,salary))颜色标记
                else:
                    print("\033[31;1myour current balance is %s ,you can't buy it\033[1m"%salary)
            else:
                print("product code %s is 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" )