python练习_购物车（简版）

　python练习_购物车（简版）

需求：

1. 写一个python购物车可以输入用户初始化金额
2. 可以打印商品，且用户输入编号，即可购买商品
3. 购物时计算用户余额，是否可以购买物品
4. 退出结算时打印购物小票

以下代码实现的功能与思路：

功能：　

　　（1）预算金额控制，只能输入大于0的数字
　　（2）商品格式化打印
　　（3）选择完成要买的商品后，提示用户再次确认，确认后开始计算用户余额是否大于等于商品价格，价格正确后则加入购物车
　　（4）输入q则进行结算，结算时将重复的商品进行合并，显示个数，并计算消费总额和余额

思路：

　　（1）商品打印通过嵌套列表实现

　　（2）购买商品是只需要比较用户余额和商品价格即可，如果比商品金额打就把这个商品加入到一个列表中

　　（3）结算时计算用户购物车列表即可

流程图：

使用方法：

　　执行环境：Python3.5

　　执行方法，执行执行即可

代码：

 #!/usr/bin/env python
 # -*- coding: utf-8 -*-

 import time

 List_items = [ ["iPhone4",100],["iPhone5",200],["iPhone6",300],["iPhone7",4000],["Python",10000],]
 User_shopping_cart = []

 def in_money():
     '''
     判断用户输入金额的函数
     '''
     global user_in_money
     while True:
         user_in_money = input("Please enter initial funds:").strip()
         if user_in_money.isdigit():
             if int(user_in_money) > 0:
                 while True:
                     print_lists()
             else:
                 print("\033[31mInput Error!\033[0m")
         else:
             print("\033[31mInput Error!\033[0m")

 def print_lists():
     '''
     获取用户输入的编号，调用结算模块
     :return:
     '''
     print("Product List".center(40,"-"))
     Spaces = " "*2
     for Product_info in List_items:
         Underlined = 20-len(Product_info[0])
         print(Spaces,List_items.index(Product_info)+1,Spaces,Product_info[0],"."*Underlined,Product_info[1])
     print("-"*40)

     in_Numbering = input("Please enter the product number,[q]exit billing:").strip()
     if in_Numbering.isdigit():
         if int(in_Numbering) > 0 and int(in_Numbering)<= len(List_items):
             Transaction_Calculations(in_Numbering)
         else:
             print("\033[31mThe item number does not exist!\033[0m")
     else:
         if in_Numbering == "q":
             settlement()
         else:
             print("\033[31mInput Error!\033[0m")

 def Transaction_Calculations(Numbering):
     '''
     加入购物车模块，判断用户余额是否足够购买商品
     '''
     global user_in_money
     user_in_money = int(user_in_money)
     Numbering = int(Numbering)
     Pu_confirmation = input("Product \033[32m%s\033[0m Whether to add to cart(y/n):"%List_items[Numbering-1][0]).strip()
     if Pu_confirmation == "y":
             if user_in_money >= List_items[Numbering-1][1]:
                 User_shopping_cart.append(List_items[Numbering-1])
                 user_in_money = user_in_money - List_items[Numbering-1][1]
                 print("Product %s Added Cart, Current Balance %s¥"%( List_items[Numbering-1][0],user_in_money))
             else:
                 print("The balance is insufficient, the commodity price \033[31m%s\033[0m￥,lacks \033[31m%s\033[0m￥"%(List_items[Numbering-1][1],List_items[Numbering-1][1]-user_in_money))
     else:
         print("\033[31mNot added to cart\033[0m")

 def settlement():
     '''
     结算模块
     '''
     if len(User_shopping_cart) == 0:
         print("Shopping Cart There are no products, thank you patronage goodbye")
         exit()
     else:
         print("Shopping list".center(50,"-"))
         consumption = 0
         new_user = []
         [new_user.append(i) for i in User_shopping_cart if not i in new_user]
         for user_cart in new_user:
             number = User_shopping_cart.count(user_cart)
             settlement_un = 15-len(user_cart[0])
             to_settlement_un = 25 - settlement_un - len(str(user_cart[1])) - len(user_cart[0])
             consumption += user_cart[1]*number
             print(" "*5,user_cart[0],"."*settlement_un,user_cart[1],"￥","."*to_settlement_un,"%s个"%(number))
         times = time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(time.time()))
         print(times.center(50,"-"))
         print("Shopping cost \033[32m%s\033[0m¥, Current balance \033[32m%s\033[0m¥,Thank you to patronize!".center(50,"-")%(consumption,user_in_money))
         exit()

 if __name__ == "__main__":
     in_money()

购物车