''''' 
Created on 2017年9月4日 
 
@author: len 
''' 
 
 
product_list = [ 
 ('Robot',200000), 
 ('MacPro',12000), 
 ('Iphone8',8888), 
 ('Hello World',1200), 
    ] 
shopping_list = [] 
user_salary=input("请输入你的工资：") 
if user_salary.isdigit(): 
 user_salary = int(user_salary) 
 while True: 
  print("商品如下：") 
  for index,item in enumerate(product_list): 
    
   print (index,item) 
  user_choice = input("请输入要购买的商品编号：") 
  if user_choice.isdigit(): 
   user_choice = int(user_choice) 
   if user_choice < len(product_list) and user_choice > -1: 
    p_item = product_list[user_choice] 
    if user_salary>=p_item[1]: 
     shopping_list.append(p_item) 
     user_salary-=p_item[1] 
     print("购买商品",p_item,"成功您的余额为",user_salary,"元！" ) 
    else: 
     print("您的余额为",user_salary,"余额不足以购买此商品，购买失败！") 
        
   else: 
    print("并无此产品！") 
  elif user_choice == "q": 
   print("--------shopping list-------") 
   for i in shopping_list: 
    print(i) 
   exit() 
  else: 
   print("invalidate！！！")