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("33[31mInput Error!33[0m")
        else:
            print("33[31mInput Error!33[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("33[31mThe item number does not exist!33[0m")
    else:
        if in_Numbering == "q":
            settlement()
        else:
            print("33[31mInput Error!33[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 33[32m%s33[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 33[31m%s33[0m￥,lacks 33[31m%s33[0m￥"%(List_items[Numbering-1][1],List_items[Numbering-1][1]-user_in_money))
    else:
        print("33[31mNot added to cart33[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 33[32m%s33[0m¥, Current balance 33[32m%s33[0m¥,Thank you to patronize!".center(50,"-")%(consumption,user_in_money))
        exit()

if __name__ == "__main__":
    in_money()