架构
shopcar
admin.py > 管理类
存储用户字典 用户id作为键 用户对象作为值
注册 登录 购物车添加商品 购物车删除商品 结算购物车 注销
goods.py > 商品类
商品属性：商品名称 商品价格 商品数量
shopcar.py > 购物车类
存储商品字典
商品对象作为键 商品数量作为值
storage.py > 仓库类
存储商品列表
列表中的元素是商品对象
user.py > 用户类
用户属性：用户id 用户名 用户密码 购物车 状态(登录与否)
main.py > 入口
调用管理类的功能进行界面操作
resources > 数据库
存储商品信息 用户信息
构造有点复杂 涉及大量的文件操作 出错率很高 先实现几个简单的模块吧
代码实现
goods.py
class Goods:
# 限制动态添加属性
__slots__ = ("gname", "gprice", "gnum")
def __init__(self, gname, gprice, gnum):
self.gname = gname
self.gprice = gprice
self.gnum = gnum
def __str__(self):
return f'商品名:{self.gname}, 商品价格:{self.gprice}, 商品数量:{self.gnum}'
# __str__显示给用户
# __repr__显示给开发人员
# 定义__repr__
__repr__ = __str__user.py
class User:
__slots__ = ("uid", "uname", "upassword", "ushopcar", "login")
def __init__(self, uid, uname, upassword, ushopcar):
self.uid = uid
self.uname = uname
self.upassword = upassword
self.ushopcar = ushopcar
self.islogin = False
def __str__(self):
return f'用户id:{self.uid}\n用户名:{self.uname}\n用户登录状态:{self.islogin}'
__repr__ = __str__shopcar.py
class ShoppingCar:
# 元组只有一个元素需要添加,
__slots__ = ("goods_dict",)
def __init__(self):
self.goods_dict = {}
def __str__(self):
return f'购物车:{self.goods_dict}'
__repr__ = __str__单例模式
storage.py
import os
import pickle
from goods import Goods
path = 'resources/goods_list.txt'
# 单例装饰器
def singleton(cls):
instance = None
def get_instance(*args, **kwargs):
nonlocal instance
if not instance:
instance = cls(*args, **kwargs)
return instance
return get_instance
# 限制只能有一个仓库实例
@singleton
class Storage:
__slots__ = ("goods_list",)
def __init__(self):
self.goods_list = None
self.load_goods()
def load_goods(self):
if not os.path.exists(path):
self.goods_list = []
names_list = ['iPhone14', 'iPhone13', 'iPhone12', 'iPhone11']
prices_list = [8000, 7000, 6000, 5000]
nums_list = [50, 40, 30, 20]
for i in range(len(names_list)):
goods = Goods(names_list[i], prices_list[i], nums_list[i])
self.goods_list.append(goods)
self.save_goods()
else:
self.load_goods()
def save_goods(self):
with open(path, 'wb') as f:
pickle.dump(self.goods_list, f)
def load_goods(self):
with open(path, 'rb') as f:
self.goods_list = pickle.load(f)核心模块
admin.py
from user import User
import os
import pickle
import uuid
from shopcar import ShoppingCar
from storage import Storage
from goods import Goods
path = 'resources/user.txt'
class Admin:
__slots__ = ("user_dict",)
def __init__(self):
self.user_dict = None
self.load_users()
def load_users(self):
if os.path.exists(path):
with open(path, 'rb') as f:
self.user_dict = pickle.load(f)
else:
self.user_dict = {}
def save_users(self):
with open(path, 'wb') as f:
pickle.dump(self.user_dict, f)
@property
def __get_uid(self):
while 1:
# 使用uuid模块随机生成用户的uid
uid = str(uuid.uuid4()).split('-')[1]
# 确保uid唯一
if uid not in self.user_dict:
print(f'当前用户的uid是{uid}')
return uid
def user_register(self):
uid = self.__get_uid
name = input('请输入用户名:')
password = input('请输入密码:')
shopcar = ShoppingCar()
user = User(uid, name, password, shopcar)
self.user_dict[uid] = user
# 保存数据
self.save_users()
print('注册成功')
def user_login(self):
uid = input('请输入用户uid:')
if uid not in self.user_dict:
print('用户不存在 请先注册')
return
user = self.user_dict[uid]
if user.islogin:
print('用户已登录')
return user
cnt = 0
while 1:
cnt += 1
# 三次输入机会
if cnt > 3:
print('输入错误次数过多 禁止登录')
return
name = input('请输入用户名:')
password = input('请输入密码:')
if name == user.uname and password == user.upassword:
print('登录成功')
# 设置登录状态
user.islogin = True
self.user_dict[user.uid] = user
self.save_users()
# 返回登录后的用户
return user
else:
print('用户名或密码错误')
def add_goods(self):
'''
同步仓库和购物车的数据
'''
user = self.user_login()
if not user:
print('您还未登录 请先登录')
return
# 添加商品会减少库存
storage = Storage()
print('商品列表如下:')
# 库存中的商品对象
for i in range(len(storage.goods_list)):
print(f'{i}.{storage.goods_list[i]}')
i = input('请输入要购买的商品编号:')
if i.isdigit():
i = int(i)
if i in range(len(storage.goods_list)):
goods = storage.goods_list[i]
n = int(input(f'请输入要购买的{goods.gname}商品数量:'))
if n <= 0:
print('购买数量不能≤0')
else:
while n > goods.gnum:
n = int(input(f'剩余商品数量为{goods.gnum}, 库存不足\n请重新输入购买数量:'))
else:
# 购物车中的商品对象
ugoods = Goods(goods.gname, goods.gprice, n)
if ugoods in user.ushopcar.goods_dict:
user.ushopcar.goods_dict[ugoods] += n
else:
user.ushopcar.goods_dict[ugoods] = n
storage.goods_list[i].gnum -= n
storage.save_goods()
# 更新用户信息
self.user_dict[user.uid] = user
self.save_users()
print(f'{goods.gname}添加成功')
else:
print('暂无该商品')
else:
print('商品编号输入有误')
return
def del_goods(self):
user = self.user_login()
if not user:
print('您还未登录 请先登录')
return
print('您的购物车如下:')
for goods in user.ushopcar.goods_dict.keys():
print(goods)
gname = input('请输入要删除的商品名:')
# 购物车商品 仓库商品
car_goods, sto_goods = None, None
for goods in user.ushopcar.goods_dict.keys():
if goods.gname == gname:
car_goods = goods
break
else:
print(f'{gname}商品不在您的购物车中')
return
storage = Storage()
for goods in storage.goods_list:
if goods.gname == gname:
sto_goods = goods
break
n = int(input(f'请输入要删除的商品{gname}数量'))
if n >= car_goods.gnum:
user.ushopcar.goods_dict.pop(car_goods)
sto_goods.gnum += n
else:
car_goods.gnum -= n
user.ushopcar.goods_dict[car_goods] = car_goods.gnum
sto_goods.gnum += n
# 更新仓库信息
storage.goods_list[storage.goods_list.index(sto_goods)] = sto_goods
storage.save_goods()
# 更新购物车信息
self.user_dict[user.uid] = user
self.save_users()
print(f'{gname}删除成功')
def buy_goods(self):
user = self.user_login()
if not user:
print('您还未登录 请先登录')
return
total_price = 0
for goods, num in user.ushopcar.goods_dict.items():
total_price += goods.gprice * num
print(f'总价格是￥{total_price}')
# 清空用户购物车
user.ushopcar.goods_dict.clear()
self.user_dict[user.uid] = user
self.save_users()
print('结算成功')
def user_logout(self):
user = self.user_login()
if user:
user.islogin = False
self.user_dict[user.uid] = user
self.save_users()
print('退出登录成功')
else:
print('用户读取失败')main.py
from admin import Admin
def main():
admin = Admin()
print('欢迎登录千锋购物系统'.center(30, '*'))
print('''
1.用户注册
2.用户登录
3.购物车添加商品
4.购物车删除商品
5.结算购物车中的商品
6.注销用户
7.退出系统
''')
while 1:
op = input('请选择您想进行的操作:')
if op == '1':
admin.user_register()
elif op == '2':
admin.user_login()
elif op == '3':
admin.add_goods()
elif op == '4':
admin.del_goods()
elif op == '5':
admin.buy_goods()
elif op == '6':
admin.user_logout()
elif op == '7':
print('退出成功')
exit()
else:
print('当前操作不合法')版权声明：本文为qq_45580637原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接和本声明。