购物车程序更新：

更新商家入口，实现以下功能：

1. 商家能够修改商品价格；

2. 商家能够下线商品；

3. 商家能够增加商品；

4. 商品信息存在文件中

 

1 # -*- coding:utf-8 -*- 2 # LC 3 product_list = [] 4 product_line = [] 5 count = 0 6  7 with open("product_list","r") as f:                     #打开商家货品清单文件 8     for item in f: 9         product_line = item.rstrip().split(",")            #将每行赋值给成一个列表，以“，”区分10         product_list.append(product_line)                   #将每行的列表加入product_list列表中11 12 print("This is your production".center(50,"-"))         #打印列表13 for i in product_list:14     print(count,i)15     count+=116 17 #提供增加商品，修改商品价格，删除商品功能18 while True:19     select = input("Please input you selection,'a' to add,'m' to modified the price,'d' to Delete,'q' to quit :")20     count = 021     if select == 'a':22         add_product = input("Please input new product name:")23         add_price = input("Please input new product price:")24         new_product = [add_product,add_price]                       #将新添加的商品赋值成列表25         product_list.append(new_product)                            #向产品清单列表中插入新添加的商品26         with open("product_list","a") as f_add:                 #将添加的商品写入文件中，以追加的方式27             f_add.writelines(product_list[-1][0]+","+product_list[-1][1]+"\n")28         print("\033[1;31mThis is your new production list\033[0m".center(50,"-"))29         for i in product_list:       #打印新的产品清单30             print(count,i)31             count+=132     elif select == 'm':33         modify_index = input("Please input index of the item which you want to modify:")    #输入要修改价格的产品序号34         modify_index = int(modify_index)35         length = product_list.index(product_list[-1])   #判断输入的修改价格产品序号是否再产品清单范围36         if 0 <= modify_index <= length:37             new_price = input("Please input the new price:")                    #输入新的价格38             product_list[modify_index][1]=new_price                                 #将新的价格修改至产品清单列表中39             with open("product_list","w") as f_modify:                          #想修改的产品清单列表写入文件中40                 for i in product_list:41                     f_modify.writelines(i[0]+","+i[1]+"\n")42             print("\033[1;31mThis is your new production list\033[0m".center(50,"-"))43             for i in product_list:                                        #打印新的产品清44                 print(count,i)45                 count+=146         else:47             print("Your select is invalid, Please try again!")      #如果输入的序号不在范围内，则报错重新来48     elif select == 'd':                                             #删除商品49         delete_index = input("Please input index of the item which you want to delete:")50         delete_index = int(delete_index)51         length = product_list.index(product_list[-1])               #判断输入的删除序号是否再产品清单范围52         if 0 <= delete_index <= length:53             product_list.pop(delete_index)                      #从产品清单中删除制定的产品54             with open("product_list","w") as f_del:55                 for i in product_list:56                     f_del.writelines(i[0]+","+i[1]+"\n")           #将新的产品清单写入文件中57             print("\033[1;31mThis is your new production list\033[0m".center(50,"-"))58             for i in product_list:59                 print(count,i)60                 count+=161         else:62             print("Your select is invalid, Please try again!")63 64     elif select == "q":65         print("You have been quit!")66         break67     else:68         print("invalid input,please input again!")

pic,2rice,3water,32phone,5000pia,300

更新用户购买程序，实现以下功能：

1. 用户第一次购买输入薪资；

2. 用户购买商品信息写入文件；

3. 用户再次购买先读取之前的购买清单文件，查看余额；

1 # -*- coding:utf-8 -*- 2 # LC 3 import os 4 product_list = []           #定义商品清单列表 5 product_line = []           #定义商品清单中每行的列表 6 user_buy_list = []          #定义用户已经购买商品列表 7 user_buy_product = []       #定义用户购买单个商品的列表 8 with open("product_list","r") as f_production:              #读取商品清单列表 9     for item_production in f_production:10         product_line = item_production.rstrip().split(",")11         product_list.append(product_line)12 13 if os.path.getsize("shopping_list") == 0:                       #判断是否为第一次消费，如果消费清单文件为空，则第一次消费14     salary = input("Please input your salary:")15     balance = int(salary)                                           #将余额定义为薪资16 else:17     length = len(open("shopping_list","rU").readlines())            #如果不是第一次消费，计算消费清单文件行数，提取消费列表18     count = 019     with open("shopping_list", "r") as f_shopping_list:20         for shopping_item in f_shopping_list:21             count +=122             if 2 <= count <= length-2:                          #去除第一行和最后两行，将消费清单中已购买的商品提取出来23                 shopping_item = shopping_item.strip().split()   #将购买的商品转换为列表，包含商品，单价，数量24                 user_buy_list.append(shopping_item)             #将已经购买的商品记录至用户消费清单列表中25             elif count == length:26                 shopping_item = shopping_item.strip().split()27                 balance = int(shopping_item[-1])                #如果非第一次消费，则余额为消费清单文件中的余额，提取出来28 while True:29     print("This is the production list".center(50, "-"))30     count = 031     for i in product_list:32         print(count, i)33         count += 134     user_select = input("Your balance is %d, 's' to start to shopping,'q' to quit : "%(balance))35     if user_select == 's':36         user_buy_product = []37         user_select_index = input("Please select the index of the one you want to buy:")        #输入要购买的商品38         user_select_count = input("Please input the number how many you want to buy:")          #输入要购买的商品数量39         user_select_index = int(user_select_index)40         user_select_count = int(user_select_count)41         unit_price = int(product_list[user_select_index][1])                        #要购买的商品单价42         product_price = unit_price * user_select_count                              #购买的商品金额，即单价乘以总价43         if product_price <= balance:44             user_buy_product.append(product_list[user_select_index][0])             #将购买的商品的名称插入新的单个列表中45             user_buy_product.append(product_list[user_select_index][1])             #将购买的商品的单价插入新的单个列表中46             user_buy_product.append(str(user_select_count))                         #将购买的商品的数量插入新的单个列表中47             user_buy_list.append(user_buy_product)                                  #将新购买的商品，包含名称，单价，数量插入用户购买清单中48             balance = balance - product_price                                        #将金额出去已经购买的商品金额，以免余额不足49         else:                                                                       #购买的商品和数量，余额不足50             print("\033[1;31mYour choice is out of your money!\033[0m")51             continue52     elif user_select == 'q':53         break54     else:55         print("invalid input ,try again")56         continue57 58 #统计用户购买商品的总金额和消费余额59 total_price = 060 for i in user_buy_list:61     user_buy_product_price = int(i[1]) * int(i[2])          #用户购买的单个商品的总额，即单件商品的单价乘以数量62     total_price = total_price + user_buy_product_price      #统计消费总金额63 total_consumption = ["Total_Consumption:"]64 balance_list = ["Your balance:"]                            #消费清单上记录余额信息65 balance_list.append(balance)66 total_consumption.append(total_price)67 user_buy_list.append(total_consumption)                     #将总消费金额信息插入用户消费清单中68 user_buy_list.append(balance_list)                          #将余额信息插入用户消费清单中69 70 #将用户购买的商品写入消费清单文件中，并记录总价和余额71 with open("shopping_list","w") as f_buy:72     f_buy.writelines("product".center(15,"-")+"price".center(15,"-")+"count".center(15,"-")+"\n")73     for i in user_buy_list:74         if len(i) == 3:                     #将商品写入75             f_buy.writelines(str(i[0]).center(15," ")+str(i[1]).center(15," ")+str(i[2]).center(15," ")+"\n")76         else:                               #将余额和消费总额写入77             f_buy.writelines(str(i[0]).ljust(30, " ") + str(i[1]).center(15, " ") + "\n")78 79 #打印最终购买清单80 print("This is your purchase list".center(45,"-"))81 with open("shopping_list","r") as f_read:82     for i in f_read:83         print(i.strip("\n"))

购买清单文件

----product---------price----------count-----      pic             2              20            rice            3              50           water            32            300           phone           5000            2             pia            300             50           phone           5000            2            phone           5000            1       Total_Consumption:                 49790     Your balance:                       210