python简单的购物系统

#coding = utf-8
#2016-11-19
#我的工资是存在文件中的，执行后会判断是否存过工资，如果存过无需输入，直接购物，没存过需要输入工资
#wages.txt是存工资的文件
import os

product_list = [
    ['iphone6', 5888],
    ['联想笔记本', 8000],
    ['iphone7', 6888],

]
shop_car = []
if os.path.getsize ('wages.txt'):  # 判断是否写入工资
    money = open ('wages.txt', 'r', encoding='utf-8')
    your_money = money.readline ()
    money.close ()

    while True:
        for item,p in enumerate (product_list):

            print (item, p[0], p[1])

        user_choice = input ('请输入要购买的商品编号，按q退出：')
        if user_choice.isdigit ():
            user_choice = int (user_choice)
            p_price = product_list[user_choice][1]
            your_money = int(your_money)
            if  p_price < your_money:
                shop_car.append(product_list[user_choice])

                your_money -= p_price
                with open ('wages.txt', 'w', encoding='utf-8') as m:
                    m.write(str(your_money))
                print('加入购物车，剩余%d'%your_money)
            else:
                print('工资不够，努力赚钱')
        elif user_choice == 'q':
            for k,v in enumerate(shop_car):
                print(k,v)
            print('剩余钱数%d'%your_money)
            exit()
        else:
            print('参数不正确,请重新选择')
else:
    your_money = input('请输入你的工资')
    if your_money.isdigit:
        your_money = int (your_money)
        with open ('wages.txt', 'w', encoding='utf-8') as money:
            money.write (str (your_money))
    while True:
        for item, p in enumerate (product_list):

            print (item, p[0], p[1])

        user_choice = input ('请输入要购买的商品编号，按q退出：')
        if user_choice.isdigit ():
            user_choice = int (user_choice)
            p_price = product_list[user_choice][1]
            if p_price < int(your_money):
                shop_car.append (product_list[user_choice])
                your_money -= p_price
                with open ('wages.txt', 'w', encoding='utf-8') as m:
                    m.write (str (your_money))
                print ('加入购物车，剩余%d' % your_money)
            else:
                print ('工资不够，努力赚钱吧小伙')
        elif user_choice == 'q':
            for k, v in enumerate (shop_car):
                print (k, v)
            print ('剩余钱数%d' % your_money)
            exit ()
        else:
            print ('参数不正确,请重新选择')
    else:
        exit ('您的工资不合法：')