需求：
用户入口：
1、商品信息放在文件中，从文件中读取
2、已购商品，余额记录，第一要输入起始金额，以后不需要二次输入
商家入口：
2、可以添加商品，修改商品价格
1 # Author:Lee Sirimport sys 2 3 4 def goods_info(): 5 goods_info = 'goods_info.txt' 6 fd = open(goods_info) 7 return fd 8 9 def goods_list(fd): 10 print('商品列表'.center(30,'-')) 11 for items in fd.readlines(): 12 index,goods_name,goods_price = items.split() 13 print(index,goods_name,goods_price) 14 15 def check_cart(buylist): 16 print('您的购物车如下：') 17 for name,price in buylist: 18 print('名称：',name,'价格：',price) 19 check_choice = input('是否结账？：[Y/N]') 20 if check_choice == 'y' or check_choice == 'Y': 21 return True 22 else: 23 return False 24 25 def check_money(money,buylist): 26 money = int(money) 27 chech_result = 0 28 for name,price in buylist: 29 chech_result += int(price) 30 if chech_result <= money: 31 return True,money - chech_result 32 else: 33 return False,money 34 35 36 def buyer(): 37 buylist = [] 38 while True: 39 money = input("请输入的金钱：") 40 if money.isdigit(): 41 while True: 42 money = int(money) 43 fd = goods_info() 44 goods_list(fd) 45 choice = input('请输出你要购买的商品序号：') 46 if choice.isdigit(): 47 choice = int(choice) 48 # print(type(choice)) 49 fd.seek(0) 50 if choice > 0 and choice <= len(fd.readlines()): 51 fd.seek(0) 52 #print('1') 53 for items in fd.readlines(): 54 index, goods_name, goods_price = items.split() 55 if int(index) == choice: 56 buylist.append((goods_name,goods_price)) 57 print('添加 %s 至购物车。' % (goods_name)) 58 buy_choice = input('是否继续购买? [Y/N]') 59 if buy_choice == 'y' or buy_choice == 'Y': 60 continue 61 else: 62 if len(buylist) > 0: 63 if check_cart(buylist): 64 check_result, balance = check_money(money,buylist) 65 if check_result: 66 exit('结算成功，您的余额还有 %s' % balance ) 67 else: 68 continue_buy = input('您的余额不足，是否修改购物车？: [Y/N]') 69 if continue_buy == 'Y' or continue_buy == 'y': 70 print('您的购物车如下：') 71 for index,buy_name in enumerate(buylist): 72 name,price = buy_name 73 print('序号：',index,'名称：', name, '价格：', price) 74 else: 75 while True: 76 dele_cart = input('请输入你要删除的产品序号：') 77 if dele_cart.isdigit(): 78 dele_cart = int(dele_cart) 79 if dele_cart >= 0 and dele_cart <= len(buylist): 80 buylist.remove(dele_cart) 81 break 82 else: 83 print('输入错误请重新输入') 84 else: 85 print('输入错误，请重新输入') 86 87 else: 88 continue_check = input('您的购物车为空，是否继续购买? [Y/N]') 89 if continue_check == 'Y' or continue_check == 'y': 90 continue 91 else: 92 exit('See you tomorrow!') 93 else: 94 print('输入有误，请重新输入：') 95 96 else: 97 exit('您没有购买任何产品，再见！') 98 else: 99 print('输入有误，请重新输入') 100 101 102 buyer()