goods_list = [ {'name':'iphone','price':4500,'count':40}, {'name':'手机','price':7000,'count':100}, {'name':'平板','price':5000,'count':60}, {'name':'羽绒服','price':500,'count':80}, {'name':'衣服','price':1000,'count':90}, {'name':'帽子','price':200,'count':120}, {'name':'oppo','price':2000,'count':200}, {'name':'电动车','price':2100,'count':300}] shopping_list = [] info = """----- supermarket info ----- 1.Please enter the goods number you want to buy 2.input quit to quit 3.input check to check your shop cart 4.input good to see goods """ print(info) while True: money = input("please input your money:") if money.isdigit(): if int(money) >= 0: money = int(money) break else: print("input money is wrong!") continue def good(): for i, item in enumerate(producty_list): print(i, item) good() while True: buy = input("input the good number ,or quit or check:") if buy == 'quit': print("good bye") break if buy == 'good': good() continue elif buy == 'check': print("Shop cart has", shopping_list) continue if buy.isdigit(): buy = int(buy) if buy in range(len(producty_list)): if money >= producty_list[buy][1]: producty_name = producty_list[buy][0] money -= producty_list[buy][1] shopping_list.append(producty_list[buy][0]) print("{0} has added to your shoppong cart,you have {1} yuan left.".format(producty_name, money)) else: print("you don't have enough money!") else: print("There's no goods you want here") else: print("I cant understand what you want to buy.....")