# 商品类
class Goods(object):
 def __init__(self,name,price,stock):
 self.id = 0
 self.name = name
 self.price = price
 self.stock = stock
 # 当打印对象时，输出的内容
 def __str__(self):
 return 'id:%s\n' \
  '名称:%s\n' \
  '价格:%s\n' \
  '库存:%s\n' % (self.id,self.name,self.price,
    self.stock)
 
 
if __name__ == '__main__':
 goods = Goods('Apple pods',2999,100)
 print(goods)
 goods2 = Goods('Apple Watch',3666,100)
 print(goods2)

from goods import Goods
 
class CartItem(object):
 # 购物车商品
 def __init__(self,goods,count):
 self.goods = goods
 self.count = count
 
 def __str__(self):
 # %f是小数类型的占位符
 return '%s(￥%.2f)*%s' % (self.goods.name,
     self.goods.price,self.count)
 
 # 计算商品小计
 def amout(self):
 return self.goods.price * self.count
 
 
if __name__ == '__main__':
 goods = Goods('Apple pods',2999,100)
 # 创建购物车商品对象，需要传入一个商品对象
 item = CartItem(goods,2)
 money = item.amout()
 print(money)

from goods import Goods
from cart import CartItem
 
class Shop(object):
 """商店"""
 def __init__(self):
 # 存储所有商品
 self.shops = []
 # 存储购物车商品
 self.cart = []
 # 加载商品
 self.load()
 
 def load(self):
 """加载商品"""
 self.add(Goods('Apple Watch', 3299, 100))
 self.add(Goods('AirPods', 1288, 100))
 self.add(Goods('Home Pod', 1299, 100))
 self.add(Goods('iPhone X', 6288, 100))
 
 def add(self, good):
 """
 设置新商品的id，添加到列表中
 :param good: 新商品
 :return: None
 """
 good.id = len(self.shops) + 1
 self.shops.append(good)
 
 def print_line(self):
 
 print('-'*50)
 
 def print_double_line(self):
 print('='*50)
 
 def list(self):
 """列出所有商品"""
 print('请选择商品：')
 self.print_double_line()
 # 遍历商品列表
 for g in self.shops:
 
  print('%s %s %s' % (g.id, g.name, g.price))
  self.print_line()
 
 def list_cart(self):
 """展示购物车商品，计算总价"""
 self.print_line()
 total = 0.0
 for item in self.cart:
  print('%s =￥%s' % (item, item.amout()))
  total += item.amout()
 self.print_line()
 print('总金额：￥%.2f' % total)
 
 def add_to_cart(self):
 """添加商品到购物车"""
 print('\n')
 g_id = input('请输入商品Id（回车去结账，0清空购物车）：')
 
 if len(g_id) == 0:
  # 结账
  total = 0.0
  for item in self.cart:
 
  total += item.amout()
  self.print_line()
  print('请支付：￥%.2f' % total)
 
  # 清空购物车
  self.cart.clear()
  print('支付成功！')
 
 elif g_id == '0':
  self.cart.clear()
  print('购物车已清空！')
 else:
  # 计算商品索引
  idx = int(g_id) - 1
  # 取出商品
  goods = self.shops[idx]
  self.print_line()
  print(goods)
 
  count = int(input('请输入购买数量：'))
  # 判断数量是否大于库存量
  while count > goods.stock:
  count = int(input('没有这么多商品，请重新输入：'))
 
  # 如果商品已经在购物车中，修改商品数量
  # 变量表示在购物车中是否有这个商品
  is_exsts = False
  for item in self.cart:
  if item.goods == goods:
   # 说明在购物车中有该商品
   is_exsts = True
   item.count += count
   # 减少库存
   goods.stock -= count
 
  # 如果执行到这，is_exsts的值还是False，说明购物车中没有该商品
  if is_exsts == False:
  # 把商品添加到购物车
  goods.stock -= count
  self.cart.append(CartItem(goods, count))
 
  # 展示购物车商品，计算总价
  self.list_cart()
 
 def run(self):
 """运行应用程序"""
 print('智游电子产品商店')
 print('v1.0')
 print('\n')
 
 self.list()
 
 while True:
  self.add_to_cart()
 
shop = Shop()
shop.run()