Python编写购物小程序

购物车要求:

       用户名和密码存放于文件中
       启动程序后，先登录，登录成功则让用户输入工资,然后打印商品列表，失败则重新登录，超过三次则退出程序
       允许用户根据商品编号购买商品
       用户选择商品后，检测余额是否够，够就直接扣款，不够就提醒
       可随时退出，退出时，打印已购买商品和余额

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

import os
'''
用户名和密码存放于文件中
启动程序后，先登录，登录成功则让用户输入工资,然后打印商品列表，失败则重新登录，超过三次则退出程序
允许用户根据商品编号购买商品
用户选择商品后，检测余额是否够，够就直接扣款，不够就提醒
可随时退出，退出时，打印已购买商品和余额
'''

product_dic = { 1:['Iphone7',5800],
                2:['Coffee',30],
                3:['疙瘩汤',10],
                4:['Python Book',99],
                5:['Bike',199],
                6:['ViVo X9',2499],
}

shop_list=[]
shop_dic={}
def shop():
    Tag=True
    remain_Balance = Balance
    print("开始购物".center(30,"="))
    for key,value in product_dic.items():
        print(key,value)
    while Tag:
        serial_number=input("输入你要购买商品的编号>>:").strip()
        if serial_number.isdigit():
            serial_number = int(serial_number)
            if serial_number > 6:
                print("请输入1-6")
                continue
        elif serial_number == "q":
            print("开始结算".center(20,"="))
            for list in shop_list:
                product_name = list[0]
                product_price = list[1]
                shop_dic.setdefault(product_name, {})
                shop_dic[product_name].setdefault("number", 0)
                shop_dic[product_name].setdefault("total", 0)
                shop_dic[product_name]["price"] = product_price
                if product_name in shop_dic:
                    shop_dic[product_name]["number"] += 1
                shop_dic[product_name]["total"] = shop_dic[product_name]["price"] * shop_dic[product_name]["number"]
            # 总价
            total = 0
            for product in shop_dic:
                print(product.center(7),str(shop_dic[product]["number"]).center(7),str(shop_dic[product]["total"]).center(5))
                total = total + shop_dic[product]["total"]
            print("您当前余额为{}".format(Balance).center(20))
            print("您购买总价格为{}".format(total).center(20))
            print("您的剩余价格为{}".format(Balance-total).center(20))
                # with open('user.txt',"r",encoding="utf-8") as read_f,open('.user.txt.swap',"w",encoding="utf-8") as write_f:
                #     for line in read_f:
                #         line = line.replace(str(Balnce),str(Balance-total))
                #         write_f.write(line)
                # os.remove('user.txt')
                # os.rename('.user.txt.swap', 'user.txt')
            with open('user.txt', "r", encoding="utf-8") as read_f, open('.user.txt.swap', "w",
                                                                         encoding="utf-8") as write_f:
                for line in read_f:
                    line = line.replace(str(Balance), str(Balance - total))
                    write_f.write(line)
            os.remove('user.txt')
            os.rename('.user.txt.swap', 'user.txt')
            break
        elif serial_number == "exit":
            print("直接退出")
        else:
            continue
        print("你要购买的商品编号{}，商品{},价格{}".format(serial_number,product_dic.get(serial_number)[0],product_dic.get(serial_number)[1]))
        yes_no=input("输入y/n,确定加入购物车>>:")
        if yes_no == "y" :
            if product_dic.get(serial_number)[1] > remain_Balance:
                print("您的余额不够.无法加入到购物车,还差{}".format(product_dic.get(serial_number)[1]-remain_Balance))
            else:
                shop_list.append(product_dic.get(serial_number))
                remain_Balance = remain_Balance - product_dic.get(serial_number)[1]
                print(shop_list,remain_Balance)
            continue
        elif yes_no == "n":
            print(shop_list)
            pass
            continue
        elif yes_no == "exit":
            break
        else:
            print("非法输入,请输入y或者n")
            continue

user_info={}
while True:
    print('''购物车小程序:
    1、购物
    2、注册账号
    3、充值
    输入q退出
    ''')
    option=input("your option>>:").strip()
    if not option.isdigit():
        print("input 1 or 2\n")
        continue
    option=int(option)
    if option > 2:
        print("input 1 or 2\n")
        continue

    if option == 1:
        Tag=True
        count=0
        while Tag:
            input_user = input("your name>>:").strip()
            with open("user.txt", encoding="utf-8", mode="r") as read_f:
                for line in read_f:
                    line=line.strip("\n")
                    User=line.split(",")[0]
                    Password=line.split(",")[1]
                    Balance=line.split(",")[2]
                    if input_user == User:
                        user_info.setdefault(User,{})
                        user_info[User].setdefault("count",0)
                        user_info[User]["Password"]=Password
                        user_info[User]["Balance"]=Balance
                        if user_info[User]["count"] >= 3:
                            print("%s用户锁定" %(input_user))
                            Tag=False
                        break
                else:
                    print("{}用户不存在".format(input_user))
                    continue
            if Tag:
                input_password = input("your password>>:").strip()
                if input_password == user_info[input_user]["Password"]:
                    print("{}用户密码登陆正确".format(input_user))
                    print("用户:{},余额:{}".format(User, user_info[User]["Balance"]))
                    '''
                    这时候才开始购物
                    '''
                    Balance=int(Balance)
                    shop()
                    break
                else:
                    user_info[input_user]["count"]+=1
                    print("{}用户密码登陆错误,还有{}尝试机会".format(input_user, 3 - user_info[input_user]["count"]))
    elif option == 2:
        Tag=True
        while Tag:
            with open('user.txt', "r", encoding="utf-8") as read_f, open('.user.txt.swap', "w",encoding="utf-8") as write_f:
                register_user=input("你要注册的用户>>:").strip()
                for line in read_f:
                    line=line.strip("\n")
                    User = line.split(",")[0]
                    Balance = line.split(",")[2]
                    if register_user == User:
                        print("{}用户已经存在".format(register_user))
                        yn_pay=input("是否充值y/n>>:")
                        if yn_pay == "y":
                            pay_money=input("你要充值多少>>:").strip()
                            print(Balance,pay_money)
                            print(line)
                            line=line.replace(Balance,str(int(Balance)+int(pay_money)))
                            write_f.write(line)
                            # os.remove("user.txt")
                            # os.rename('.user.txt.swap', 'user.txt')
                        elif yn_pay == "n":
                            pass

            os.remove("user.txt")
            os.rename('.user.txt.swap', 'user.txt')