Python实现购物系统实例介绍

# Author:P J J

import os

ps = '''

1 >>>>>> 修改商品

2 >>>>>> 添加商品

按q为退出程序

'''

# 打开两个文件，f文件为原来存取商品文件,f_new文件为修改后的商品文件

f = open('commodit', 'r', encoding='utf-8')

f_new = open('commodit_update', 'w+', encoding='utf-8')

file_list = f.readlines()

# 打印商品信息

while True:

 productslist = []

 # 从商品文件中读取出来的数据存放到productslist列表里

 for line in file_list:

  productname = line.strip().split()

  productname, oldprice = line.strip("\n").split()

  productslist.append([productname, int(oldprice)])

 choose = input("%s请选择：" %ps)

 if choose =='1':

  for index, item in enumerate(productslist):

   print(index, item)

  productindex = input("请输入要修改价格的商品序号:")

  if productindex.isdigit():

   productindex = int(productindex)

  while True:

   print('要修改商品信息:', productslist[productindex])

   price = input("请输入要修改的价格:")

   if price.isdigit():

    price = int(price)

    productslist[productindex][1]=price

    break

   else:

    print("请正确的输入价格！")

    continue

  #已经修改好的商品列表循环写入f_new文件夹

  for products in productslist:

   insert_data = "%s %s" %(products[0],products[1])

   f_new.write(insert_data+'\n')

  print("商品价格已经修改！")

  # 替换原来的文件

  f_new = open('commodit_update', 'r', encoding='utf-8')

  data = f_new.readlines()

  f = open('commodit', 'w+', encoding='utf-8')

  for line in data:

   f.write(line)

  f.close()

  f_new.close()

  #删除替换文件

  os.remove('commodit_update')

 elif choose =='2':

  # 添加商品

  f = open('commodit', 'a+', encoding='utf-8')

  pricename = input("请输入商品名:")

  while True:

   price = input("请输入商品价格:")

   if price.isdigit():

    f.writelines('%s %s\n' % (pricename, price))

    break

   else:

    print('输入错误请重新输入!')

    continue

  f.close()

  continue

 elif choose =='q':

  break

 else:

  print("输入错误请重新输入")

  continue

# Author:P J J

productslist = []

f = open('commodit','r',encoding='utf-8')

for line in f:

 productname,price = line.strip('\n').split()

 productslist.append((productname,int(price)))

print(productslist)

shopping_list = []

salary = input("请输入你的现金:")

if salary.isdigit():

 salary = int(salary)

 while True:

  # for item in productslist:

  #  print(productslist.index(item),item)

  for index,item in enumerate(productslist):

   print(index,item)

  #判断用户要输入

  user_choice = input("请选择要买什啥>>>:")

  if user_choice.isdigit():

   user_choice = int(user_choice)

   if user_choice < len(productslist) and user_choice >= 0:

    p_item = productslist[user_choice]

    if p_item[1] <= salary: #买得起

     shopping_list.append(p_item)

     salary -=p_item[1]

     print("加入 %s 购物车你的余额是\033[31;1m%s\033[0mRMB" %(p_item,salary))

    else:

     print("\033[32;1m 你的余额只剩[%s]RMB啦，还买个毛线\033[0m " %salary)

   else:

    print("\033[41;1m您输入的商品不存在，请重新输入!\033[0m")

  elif user_choice == 'q':

   print("----shopping_list----")

   for p in shopping_list:

    print(p)

   print("你的余额:\033[31;1m%s\033[0mRMB" %salary)

   #简单的余额记录

   f = open('salary','w+',encoding='utf-8')

   f.writelines(str(salary))

   f.close

   exit()

  else:

   print("错误选项")