2020Python练习13——函数对象和闭包函数（二）

项目操练——ATM

@2020.3.21

# 编写ATM程序实现下述功能，数据来源于文件db.txt
# 0、注册功能：用户输入账号名、密码、金额，按照固定的格式存入文件db.txt
# 1、登录功能：用户名不存在，要求必须先注册，用户名存在&输错三次锁定，登录成功后记录下登录状态（提示：可以使用全局变量来记录）

下述操作，要求登录后才能操作
# 1、充值功能：用户输入充值钱数，db.txt中该账号钱数完成修改
# 2、转账功能：用户A向用户B转账1000元，db.txt中完成用户A账号减钱，用户B账号加钱
# 3、提现功能：用户输入提现金额，db.txt中该账号钱数减少
# 4、查询余额功能：输入账号查询余额

 

import os
# 登陆
def login():
    count = 0
    while True:
        inp_user = input("账号：").strip()
        if os.path.exists(r'locked\{}.txt'.format(inp_user)):
            print("该账号已被锁定")
            count = 0
            continue
        inp_pwd = input("密码：").strip()
        msg = login_register_file(0, user=inp_user, pwd=inp_pwd)
        if msg:
            global login_user
            login_user = inp_user
            return print("登录成功")
        else:
            if msg is None:
                print("该账号不存在")
            else:
                if count == 2:
                    print("错误次数过多，账号已被锁定")
                    with open(r'locked\{}.txt'.format(inp_user), 'wt', encoding='utf-8') as f:
                        f.write('')
                    continue
                print("密码错误,剩余次数:{}".format(2-count))
                count += 1
# 注册
def register():
    while True:
        inp_user = input("账号：").strip()
        inp_pwd = input("密码：").strip()
        inp_pwd2 = input("确认密码：").strip()
        inp_money = input("金额：").strip()
        if not (inp_user or inp_pwd or inp_pwd2 or inp_money):
            print("输入不能为空")
            continue
        if inp_pwd != inp_pwd2:
            print("两次密码不一致")
            continue
        if login_register_file(1, user=inp_user, pwd=inp_pwd, money=inp_money):
            return print("注册成功")
        else:
            print("账号已存在")

# 登录注册功能实现函数
def login_register_file(acount, **kwargs):
    with open(r'db.txt', 'at', encoding='utf-8') as w, \
            open(r'db.txt', 'rt', encoding='utf-8') as r:
        if acount == 0:
            r.seek(0, 0)
            for line in r:
                user, pwd,*_ = line.strip().split(':')
                if kwargs['user'] == user and pwd:
                    if kwargs['pwd'] == pwd:
                        return True
                    else:
                        return False
            else:
                return None
        if acount == 1:
            if r:
                r.seek(0, 0)
                for line in r:
                    is_user, *_ = line.strip().split(':')
                    if kwargs['user'] == is_user:
                        return False
                else:
                    w.write('{}:{}:{}\n'.format(kwargs['user'], kwargs['pwd'], kwargs['money']))
                    return True
            else:
                w.write('{}:{}:{}\n'.format(kwargs['user'], kwargs['pwd'], kwargs['money']))
                return True

# 充值
def recharge():
    inp_money = input("请输入充值金额：").strip()
    msg = func_file('recharge', money=int(inp_money))
    if msg == 200:
        print("充值成功")
    else:
        print("充值失败")
        
# 转账
def transfer():
    inp_other = input("请输入对方账号：").strip()
    inp_money = input("请输入转账金额：").strip()
    if not is_user(inp_other):
        print("对方账号不存在")
    msg = func_file('transfer', other_user=inp_other, money=int(inp_money))
    if msg == 200:
        print("转账成功")
    else:
        print(msg)

# 提现
def withdraw():
    inp_money = input("请输入提取金额：").strip()
    msg = func_file('withdraw', money=int(inp_money))
    if msg == 200:
        print('提现成功')
    else:
        print(msg)
        
# 查询余额
def balance():
    inp_user = input("请输入你的账号：").strip()
    if inp_user == login_user:
        money = func_file('balance', user=inp_user)
        print("【{}】,您的余额为：{}元".format(login_user, money))
    else:
        print("账号错误")

def is_user(other_user):
    with open(r'db.txt', 'rb') as r:
        # 判断对方用户是否存在
        for line in r:
            user, *_ = line.decode('utf-8').strip().split(':')
            if other_user == user:
                return True
        else:
            return False

# 功能函数
def func_file(acount, **kwargs):
    with open(r'db.txt', 'rb') as r,\
        open(r'db.txt.swap', 'wb') as w:
        # 查询余额
        if acount == 'balance':
            while True:
                user, *_, money = r.readline().decode('utf-8').strip().split(':')
                if kwargs['user'] == user and money:
                    return money
        while True:
            line = r.readline()
            if len(line) == 0:
                break
            user, pwd, old_money = line.decode('utf-8').strip().split(':')
            old_money = int(old_money)
            if login_user == user and pwd and old_money:
                # 充值
                if acount == 'recharge':
                    my_money = old_money + kwargs['money']
                else:
                    # 转账以及提取金额
                    if old_money >= kwargs['money']:
                        my_money = old_money - kwargs['money']
                    else:
                        os.remove('db.txt.swap')
                        return '转账失败，余额不足'
                w.write('{}:{}:{}\n'.format(login_user, pwd, my_money).encode('utf-8'))
            else:
                # 转账后对方账户余额
                if kwargs.get('other_user') == user and pwd and old_money:
                    user_money = old_money + kwargs['money']
                    w.write('{}:{}:{}\n'.format(kwargs.get('other_user'), pwd, user_money).encode('utf-8'))
                else:
                    w.write('{}:{}:{}\n'.format(user, pwd, old_money).encode('utf-8'))
    os.remove(r'db.txt')
    os.rename('db.txt.swap', 'db.txt')
    return 200

login_user = None

func_dic={
    '1': ('充值', recharge),
    '2': ('转账', transfer),
    '3': ('提现', withdraw),
    '4': ('余额', balance),
    '5': ('登录', login),
    '6': ('注册', register),
    '0': ('退出', None)
}

def main():
    while True:
        print('ATM'.center(22, '-'))
        for i in func_dic:
            print('{} {}'.format(i, func_dic[i][0]).center(18))
        print('END'.center(22, '-'))
        cmd = input("请输入编号：").strip()
        if not cmd.isdigit():
            print("必须输入编号")
            continue
        if cmd == '0':
            break
        if cmd in func_dic:
            if login_user and cmd == '5':
                print("请勿重复登录")
                continue
            if not login_user and cmd not in ['5', '6']:
                print("请先登录")
            else:
                func_dic[cmd][1]()
            print(login_user)
        else:
            print("编号不存在")

if __name__ == '__main__':
    main()