#__Author__: "Miny Dong" #__Date__: 2019/2/26  20:36 products_list = [     ('book',100),     ('Apple',6000),     ('clothes',200),     ('watch',2000),     ('Mac Pro',8000), ] #打印商品内容 for i,v in enumerate(products_list):     print(i,v) salary = int(input("请输入您的薪资总数：")) #购物车 shopping_chart = [] #输入购买编号，循环输入，直到输入命令退出 while True:     user_choice = input("请输入商品编号(退出请输入q)：")     # 验证输入是否合法     if user_choice.isdigit():         user_choice = int(user_choice)         if (user_choice < len(products_list)) and (user_choice >= 0):             product_name = products_list[user_choice][0]             price = products_list[user_choice][1]             if price < salary:                 shopping_chart.append(products_list[user_choice])                 salary = salary - price                 print("%s已经加入到购物车，当前账户余额为%d" % (product_name, salary))             else:                 print("您的账户余额不足，余额%d元人民币。" % (salary - price))         else:             print("----请输入正确的编号(编号范围为0—%s)----" % str(len(products_list)-1))     elif user_choice=="q":         print("----------您已购买以下商品----------")         # 循环遍历购物车里的商品，购物车存放的是已买商品         for i in shopping_chart:             print(i)         print("您的余额为：%s" % salary)         break     else:         print("无效的输入")