product_list = [ ('iphone',5800), ('mac pro',12800), ('iwatch',3800), ('airpods',1200), ('baik', 800), ('book',20) ] shopping = [] salary = input('input your salary: ') if salary.isdigit(): salary = int(salary) while True: for index,item in enumerate(product_list): #enumerate显示下标 print(index,item) user_choice = input('please select a product number >>> ') if user_choice.isdigit(): #判断输入的是否数字 user_choice = int(user_choice) if user_choice < len(product_list) and user_choice >= 0: #选择商品编号 p_item = product_list[user_choice] #通过商品编号判断价格 if p_item[1] < salary: shopping.append(p_item) salary -= p_item[1] print("Added %s into shopping cart,your current balance is 33[31;1m%s 33[0m" %(p_item,salary)) else: print('