自己写的import sysgoods=[[1,"milk",5],[2,"bike",800],[3,"iphone",5800]]bought=[]salary=int(input("input your salary:"))for i in goods:    print(i)while 1:    id=input("input the id of goods which you want to bug:")    if id=="q":        print("购买结束了")        print("剩余金额：%s"%salary)        for i in bought:            print (i)        sys.exit()            id=int(id)    if (salary-goods[id-1][2])>0:        salary=salary-goods[id-1][2]        bought.append(goods[id-1])        print(bought)        print ("该商品购买成功")            else:        print("your balance is not enough:")      标准的：product_list=[    ('iphone',5800),    ('mac pro',9800),    ('bike',800),    ('watch',10600),    ('coffee',31)]shopping_list=[]salary=input("inpur your salary:")if salary.isdigit():    salary=int(salary)    while 1:        for index,item in enumerate(product_list):            print(index,item)        user_choice=input("选择要买啥？：")        if user_choice.isdigit():            user_choice=int(user_choice)            if 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 shopping cart,your current salary is %s"%(p_item[0],salary))                else:                    print("你的余额不够了")            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")