第一个 购物车程序

import json
import os
import re
# 数据结构：
goods = [
    {"name": "电脑", "price": 1999},
    {"name": "鼠标", "price": 10},
    {"name": "游艇", "price": 20},
    {"name": "美女", "price": 998},
]


# 功能要求：
# 基础要求：
# 1、启动程序后，输入用户名密码后，让用户输入工资，然后打印商品列表
# 2、允许用户根据商品编号购买商品
# 3、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
# 4、可随时退出，退出时，打印已购买商品和余额
# 5、在用户使用过程中， 关键输出，如余额，商品已加入购物车等消息，需高亮显.

# 扩展需求：
# 1、用户下一次登录后，输入用户名密码，直接回到上次的状态，即上次消费的余额什么的还是那些，再次登录可继续购买
# # 2、允许查询之前的消费记录

#查询
def query(name,pwd,shopping_list=None,balance=None):
    with open("user_name", "r", encoding='utf_8') as read_f:
        name_list = []
        for readline in read_f:
            load_list = json.loads(readline)
            user_name_str = load_list[0]['name']
            user_pwd_str = load_list[0]['pwd']
            if name == user_name_str and pwd == user_pwd_str:
                return load_list, []
            if name != user_name_str or pwd != user_pwd_str:
                name_list.append(user_name_str)
        return [{}], name_list

# 用来向文件 添加用户
def add(name, pwd):
    with open('user_name', 'a', encoding='utf_8') as add_f:
        # initial_list = [{"flag": "true"}, {"balance": 0}, {"con_record": []}]
        initial_list = [0, {"flag": "true"}, {"balance": 0}, {"con_record": []}]
        add_dic = {'name': name, 'pwd': pwd}
        initial_list[0] = add_dic
        add_f.write(json.dumps(initial_list))
        add_f.write('
')

# 这个是注册用户的函数
def reg_user_name(args):
    print('该账户不存在 是否注册')
    tag = False
    while not tag:
        choice = input('Y是N否:').upper()
        if choice == 'Y':
            reg_username = input('请输入您的用户名(只能用字母或者数字)：')
            reg_pwd = input('请输入您的密码(只能用字母或者数字)：')
            if reg_username in args:
                print('该用户已存在，请重新输入')
                continue
            if reg_username.isalnum() and reg_pwd.isalnum():    #
                add(reg_username, reg_pwd)
                print('注册成功')
                break
            else:
                print('输入的可能有非法字符，是否重新输入')
                continue
        if choice == 'N':  # 不注册就直接退出
            return

# 这个是购物车函数
def shopping(balance):
    shopping_cart = []   #定义购物车列表
    exit_flag = False
    while not exit_flag:
        print('--------商品列表--------')
        for index, i in enumerate(goods):
            print(index, i['name'], i['price'])
        choice = input('请输入想要购买的商品编号（Q退出）：').upper()
        if choice != 'Q' and not choice.isdigit():
            print('输入错误')
        if choice.isdigit():
            if 0 <= int(choice) < len(goods):  #判断输入的数字是否商品编号范围内
                if balance - goods[int(choice)]['price'] >= 0:  #判断是否买的起
                    balance -= goods[int(choice)]['price']   #买的起自动结算
                    shopping_cart.append(goods[int(choice)])
                    print('33[1;32;40m已经将%s加入购物车,余额还有%d33[0m' % (goods[int(choice)]['name'],balance))
                if balance - goods[int(choice)]['price'] < 0:
                    print('33[1;31;40m您现在有 %d 元，还差 %d 元,余额不足33[0m：'%(balance,abs(balance - goods[int(choice)]['price'])))
                    break
            if int(choice) >= len(goods) or int(choice) < 0:
                print('暂时没有这个商品')
        if choice == 'Q':
            for index, i in enumerate(shopping_cart):
                print('33[1;33;40m您已经加入购物车的商品有 %s 价格为 $%s33[0m' % (i['name'], i['price']))
            exit_flag = True
    return shopping_cart

#单单用来更改用户余额。
def change_balance(name):
    new_balance = 0  #将更改之后的 金额返回出去
    while True:
        money = input('请输入充值金额：')
        if money.isdecimal():
            with open('user_name', 'r', encoding='utf_8') as read_f, open('user_name_new', 'w', encoding='utf_8') as write_f:
                for readline in read_f:
                    user_info = json.loads(readline)
                    use_name = user_info[0]['name']   # 用户名
                    new_balance = int(user_info[2]['balance']) + int(money)  #金额 每次都在 上一次的基础上相加
                    if name == use_name:
                        user_info[2]['balance'] = new_balance
                    write_f.write(json.dumps(user_info))
                    write_f.write('
')
        else:
            print('请不要输入，除数字以外的乱七八糟')
            continue
        os.rename('user_name', 'user_name.bak')
        os.rename('user_name_new', 'user_name')
        os.remove('user_name.bak')
        return new_balance

# 这个是更改文件购物车和余额的函数
def change(name,shopping_list):
    total_cost = 0
    total_dict = {}  #{'电脑': ['Number', 2], '鼠标': ['Number', 2]}
    for i in shopping_list:
        total_cost += i['price']   #把所有商品的价格 总和一下
        if i['name'] in total_dict:  # 判断购买的商品是否在购物车里
            total_dict[i['name']][1] += 1  # 在购物车里，则商品对应的数量+1
        else:
            total_dict[i['name']] = ['Number',1]   #不在购物车里，则将商品信息数量加入购物车内
        # print(total_cost,total_dict)
    with open('user_name','r',encoding='utf_8') as read_f,open('user_name_new','w',encoding='utf_8') as write_f:
        for readline in read_f:
            user_info1 = json.loads(readline)
            curbalance = user_info1[2]['balance']
            if name == user_info1[0]['name']:
                money = curbalance - total_cost
                user_info1[2]['balance'] = money
                user_info1[3]['shopping_card'].append(total_dict)
            write_f.write(json.dumps(user_info1))
            write_f.write('
')
    os.rename('user_name', 'user_name.bak')
    os.rename('user_name_new', 'user_name')
    os.remove('user_name.bak')



if __name__ == '__main__':
    msg = '''
    1:购买商品
    2:查询账户余额
    3:历史查询消费记录
    4:退出'''
    name = None
    pwd = None
    user_info = []
    # [{"name": "qichen", "pwd": "456"}, {"flag": "true"}, {"balance": 0}, {"shopping_card": []}]  []
    while True:
        name = input('请重新输入用户名：').strip()
        pwd = input('请输入密码：').strip()
        user_info = query(name, pwd)
        if not user_info[0][0]:
            if name in user_info[1]:
                print('账户名或密码错误,重新输入')
                continue
            else:
                reg_user_name(user_info[1])
                exit('请重新登陆')
        cur_balance = user_info[0][2]['balance']   # 当前余额
        if user_info[0][0] and user_info[0][0]['name'] == name and user_info[0][0]['pwd']  == pwd:
            choice = input('33[1;35;40m您的当前余额为 %d元 是否充值,Y是N否33[0m：'%cur_balance).upper()
            if choice == "Y":
                cur_balance = change_balance(name)
                print('33[1;34;40m您的当前余额为 %d元33[0m'%cur_balance)
                break
            else:
                break
    # user_info = query(name, pwd)
    while True:
        print(msg)
        cur_balance = user_info[0][2]['balance']  # 当前余额
        choice_num = input('请选择您要做的事情：').strip()
        if choice_num.isdecimal():
            if choice_num == '1':
                shop_info = shopping(cur_balance)
                # print(shop_info)
                change(name,shop_info)
            if choice_num == '2':
                balance_info = query(name,pwd)
                print('33[1;32;40m当前余额：%s33[0m'%balance_info[0][2]['balance'])
            if choice_num == '3':
                new_user_info = query(name,pwd)
                print(new_user_info[0][3]['shopping_card'])
            if choice_num == '4':
                exit('谢谢使用')

[{"name": "qichen", "pwd": "456"}, {"flag": "true"}, {"balance": 0}, {"shopping_card": []}]
[{"name": "yuanhao", "pwd": "789"}, {"flag": "true"}, {"balance": 0}, {"shopping_card": []}]
[{"name": "peiqi", "pwd": "789"}, {"flag": "true"}, {"balance": 0}, {"shopping_card": []}]
[{"name": "xiaoya", "pwd": "789"}, {"flag": "true"}, {"balance": 0}, {"shopping_card": []}]
[{"name": "alex", "pwd": "123"}, {"flag": "false"}, {"balance": 40}, {"shopping_card": [{"u9f20u6807": ["Number", 2]}]}]

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