函数对象与闭包

1. 函数对象优化多分支if的代码练熟

def exit():
    print('退出')


def login():
    print('登录功能')


def transfer():
    print('转账功能个')


def check_balance():
    print('余额查询功能')


def withdraw():
    print('提现功能')


def register():
    print('注册功能')


func_dic = {
    '1': ('login',login),
    '2': ('transfer',transfer),
    '3': ('check_balance',check_balance),
    '4': ('withdraw',withdraw),
    '5': ('register',register),
    '0': ('exit',exit),
}


def main():
    for i, j in func_dic.items():
        print('{}:{}'.format(i, j[0]))
    while True:
        operate = input('请输入待选事项序号：')
        if not operate.isdigit():
            print('请重新输入序号')
            continue
        if operate in func_dic:
            func_dic[operate][1]()
        else:
            print('请重新输入正确序号')



main()

2. 编写计数器功能，要求调用一次在原有的基础上加一

def outter_calculate():
    n = 0

    def calculate():
        nonlocal n
        n += 1
        return n
    return calculate


calculate = outter_calculate()
print(calculate())
print(calculate())
print(calculate())
print(calculate())
print(calculate())

3. ATM程序

'''
ATM程序
# 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

login_user = None


#  注册功能
def register():
    while True:
        account_input = input('请输入注册账号：').strip()
        password_input = input('请输入密码:').strip()
        money_input = input('请输入存款额：').strip()
        with open(r'db.txt', 'rt', encoding='utf-8') as f1, 
                open(r'db.txt', 'at', encoding='utf-8') as f2:
            for line in f1:
                account, password, money = line.strip().split(':')
                if account_input == account:
                    print('账号已存在，请重新输入！')
                    break
            else:
                f2.write('
{}:{}:{}'.format(account_input, password_input, money_input))
                global login_user
                login_user = account_input
                print('账号注册成功')
                break


#  登录功能
# login_user = None


def login():
    amount = True
    n = 0
    while amount:
        account_input = input('请输入账号：').strip()
        password_input = input('请输入密码:').strip()
        with open(r'db.txt', 'rt', encoding='utf-8') as f1, 
                open(r'blacklist.txt', 'rt', encoding='utf-8') as f2:
            for line1 in f2:
                account_black, *_ = line1.strip().split(':')
                if account_black == account_input:
                    print('对不起，该账号已被锁定，程序即将退出！')
                    exit()
            else:
                for line2 in f1:
                    account, password, *_ = line2.strip().split(':')
                    if account_input == account:
                        if password_input == password:
                            global login_user
                            login_user = account_input
                            # print('登陆成功')
                            print(login_user)
                            amount = False
                            break
                        elif n == 2:
                            with open(r'blacklist.txt', 'at', encoding='utf-8') as f3:
                                f3.write('{}:{}
'.format(account_input, password_input))
                            amount = False
                            print('非常抱歉，您已输错三次密码')
                            print('您的账号已被锁定')
                            break
                        elif password_input != password:
                            n += 1
                            print('密码错误，请重新输入！')
                            print(n)
                            break
                else:
                    print('用户不存在，请先注册')
                    register()
                    amount = False


# 登录后操作
# 充值功能
def recharge():
    account = login_user
    money_input = input('请输入充值金额：').strip()
    money_input = int(money_input)
    with open(r'db.txt', 'rt', encoding='utf-8') as f1, 
            open(r'db.txt.swap', 'wt', encoding='utf-8') as f2:
        for line in f1:
            acc, *_, money = line.strip().split(':')
            money = int(money)
            if acc == account:
                line = line.replace(str(money), str(money + money_input))
                f2.write(line)
                print('充值金额为{}，余额为{}'.format(money_input, money + money_input))
            else:
                f2.write(line)
    os.remove(r'db.txt')
    os.rename(r'db.txt.swap', r'db.txt')


#  转账功能
def transfer():
    account = login_user
    account_receive = input('请输入接收账户：')
    money_input = input('请输入转账金额：')
    money_input = int(money_input)
    with open(r'db.txt', 'rt', encoding='utf-8') as f1, 
            open(r'db.txt.swap', 'wt', encoding='utf-8') as f2:
        for line in f1:
            acc, *_, money = line.strip().split(':')
            money = int(money)
            if acc == account:
                line = line.replace(str(money), str(money - money_input))
                f2.write(line)
                print('{}向{}转账{}元,{}余额为{}'.format(account, account_receive, money_input, account, money - money_input))
            elif acc == account_receive:
                line = line.replace(str(money), str(money + money_input))
                f2.write(line)
                print('{}余额为{}'.format(account_receive, money + money_input))
            else:
                f2.write(line)

    os.remove(r'db.txt')
    os.rename(r'db.txt.swap', r'db.txt')


# 提现功能
def withdraw():
    account = login_user
    money_input = input('请输入提现金额：')
    money_input = int(money_input)
    with open(r'db.txt', 'rt', encoding='utf-8') as f1, 
            open(r'db.txt.swap', 'wt', encoding='utf-8') as f2:
        for line in f1:
            acc, *_, money = line.strip().split(':')
            money = int(money)
            if acc == account:
                line = line.replace(str(money), str(money - money_input))
                print(money - money_input)
                f2.write(line)
                print('提现金额为{}，余额为{}'.format(money_input, money - money_input))
            else:
                f2.write(line)

    os.remove(r'db.txt')
    os.rename(r'db.txt.swap', r'db.txt')


# 余额查询

def remainder():
    account = login_user
    with open(r'db.txt', 'rt', encoding='utf-8') as f1:
        for line in f1:
            acc, *_, money = line.strip().split(':')
            if acc == account:
                print('余额为{}元'.format(money))


# 主程序
dic_outer = {
    '1': ('注册', register),
    '2': ('登录', login),
    '0': ('退出', None)
}

dic_inner = {
    '1': ('充值', recharge),
    '2': ('转账', transfer),
    '3': ('提现', withdraw),
    '4': ('查询余额', remainder),
    '0': ('退出', None)
}

while True:
    for i, j in dic_outer.items():
        print('{}:{}'.format(i, j[0]))
    choice_out = input('请选择操作项目').strip()
    if not choice_out.isdigit():
        print('请重新输入正确数字')
    if choice_out in dic_outer:
        if choice_out == '0':
            exit()
        else:
            dic_outer[choice_out][1]()
            if login_user == None:
                print('程序即将退出')
                break
            # print(login_user)
            while True:
                for i, j in dic_inner.items():
                    # print(login_user)
                    print('{}:{}'.format(i, j[0]))
                choice_in = input('请选择操作项目').strip()
                if not choice_in.isdigit():
                    print('请重新输入正确数字')
                if choice_in in dic_inner:
                    if choice_in == '0':
                        exit()
                    else:
                        dic_inner[choice_in][1]()

    else:
        print('数字超限，请重新输入')