product_list = [
    (‘phone1‘,5000),
    (‘phone2‘,4000),
    (‘phone3‘,3000),
    (‘phone4‘,2000),
    (‘phone5‘,1000),
    (‘phone6‘,100),
]
shopping_list = []
salary = input("your salary:")
if salary.isdigit():
    salary = int(salary)
    while True:
        for index,item in enumerate(product_list):
            print(index,item)
        user_choice = input("要什麽：")
        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 to shopping cart,your current balance is %s"%(p_item,salary))
                else:
                    print("only [%s],not enough "%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 is ",salary)
            exit()
        else:
            print("Invalid option")

shopping cart