import os

product_list = [[\'Iphone7\',5800],
                [\'Coffee\',30],
                [\'疙瘩汤\',10],
                [\'Python Book\',99],
                [\'Bike\',199],
                [\'ViVo X9\',2499],

                ]

shopping_cart={}
current_userinfo=[]

db_file=r\'db.txt\'

while True:
    print(\'\'\'
登陆
注册
购物
    \'\'\')

    choice=input(\'>>: \').strip()

    if choice == \'1\':
        #1、登陆
        tag=True
        count=0
        while tag:
            if count == 3:
                print(\'\033[45m尝试次数过多，退出。。。\033[0m\')
                break
            uname = input(\'用户名：\').strip()
            pwd = input(\'密码：\').strip()

            with open(db_file,\'r\',encoding=\'utf-8\') as f:
                for line in f:
                    line=line.strip(\'\n\')
                    user_info=line.split(\',\')

                    uname_of_db=user_info[0]
                    pwd_of_db=user_info[1]
                    balance_of_db=int(user_info[2])

                    if uname == uname_of_db and pwd == pwd_of_db:
                        print(\'\033[48m登陆成功\033[0m\')

                        # 登陆成功则将用户名和余额添加到列表
                        current_userinfo=[uname_of_db,balance_of_db]
                        print(\'用户信息为：\',current_userinfo)
                        tag=False
                        break
                else:
                    print(\'\033[47m用户名或密码错误\033[0m\')
                    count+=1

    elif choice == \'2\':
        uname=input(\'请输入用户名：\').strip()
        while True:
            pwd1=input(\'请输入密码：\').strip()
            pwd2=input(\'再次确认密码：\').strip()
            if pwd2 == pwd1:
                break
            else:
                print(\'\033[39m两次输入密码不一致，请重新输入！！!\033[0m\')

        balance=input(\'请输入充值金额：\').strip()

        with open(db_file,\'a\',encoding=\'utf-8\') as f:
            f.write(\'%s,%s,%s\n\' %(uname,pwd1,balance))

    elif choice == \'3\':
        if len(current_userinfo) == 0:
            print(\'\033[49m请先登陆...\033[0m\')
        else:
            #登陆成功后，开始购物
            uname_of_db=current_userinfo[0]
            balance_of_db=current_userinfo[1]

            print(\'尊敬的用户[%s] 您的余额为[%s],祝您购物愉快\' %(
                uname_of_db,
                balance_of_db
            ))

            tag=True
            while tag:
                for index,product in enumerate(product_list):
                    print(index,product)
                choice=input(\'输入商品编号购物，输入q退出>>: \').strip()
                if choice.isdigit():
                    choice=int(choice)
                    if choice < 0 or choice >= len(product_list):continue

                    pname=product_list[choice][0]
                    pprice=product_list[choice][1]
                    if balance_of_db > pprice:
                        if pname in shopping_cart: # 原来已经购买过
                            shopping_cart[pname][\'count\']+=1
                        else:
                            shopping_cart[pname]={\'pprice\':pprice,\'count\':1}

                        balance_of_db-=pprice # 扣钱
                        current_userinfo[1]=balance_of_db # 更新用户余额
                        print("Added product " + pname + " into shopping cart,\033[42;1myour current\033[0m balance " + str(balance_of_db))

                    else:
                        print("买不起，穷逼! 产品价格是{price},你还差{lack_price}".format(
                            price=pprice,
                            lack_price=(pprice - balance_of_db)
                        ))
                    print(shopping_cart)
                elif choice == \'q\':
                    print("""
                    ---------------------------------已购买商品列表---------------------------------
                    id          商品                   数量             单价               总价
                    """)

                    total_cost=0
                    for i,key in enumerate(shopping_cart):
                        print(\'%22s%18s%18s%18s%18s\' %(
                            i,
                            key,
                            shopping_cart[key][\'count\'],
                            shopping_cart[key][\'pprice\'],
                            shopping_cart[key][\'pprice\'] * shopping_cart[key][\'count\']
                        ))
                        total_cost+=shopping_cart[key][\'pprice\'] * shopping_cart[key][\'count\']

                    print("""
                    您的总花费为: %s
                    您的余额为: %s
                    ---------------------------------end---------------------------------
                    """ %(total_cost,balance_of_db))

                    while tag:
                        inp=input(\'确认购买(yes/no?)>>: \').strip()
                        if inp not in [\'Y\',\'N\',\'y\',\'n\',\'yes\',\'no\']:continue
                        if inp in [\'Y\',\'y\',\'yes\']:
                            # 将余额写入文件

                            src_file=db_file
                            dst_file=r\'%s.swap\' %db_file
                            with open(src_file,\'r\',encoding=\'utf-8\') as read_f,\
                                open(dst_file,\'w\',encoding=\'utf-8\') as write_f:
                                for line in read_f:
                                    if line.startswith(uname_of_db):
                                        l=line.strip(\'\n\').split(\',\')
                                        l[-1]=str(balance_of_db)
                                        line=\',\'.join(l)+\'\n\'

                                    write_f.write(line)
                            os.remove(src_file)
                            os.rename(dst_file,src_file)

                            print(\'购买成功，请耐心等待发货\')

                        shopping_cart={}
                        current_userinfo=[]
                        tag=False


                else:
                    print(\'输入非法\')


    else:
        print(\'\033[33m非法操作\033[0m\')

购物车程序面条版