会员订阅 demo

foo.py

import datetime

test_event = [
    {"event": "try", "date": "2018 01-02 12:33:23", "amount": "3d"},
    {"event": "buy", "date": "2018 04-02 12:33:23", "amount": "3m"},
    {"event": "try", "date": "2018 05-02 12:33:23", "amount": "3d"},
    {"event": "renew", "date": "2018 07-01 12:33:23", "amount": "1y"},
    {"event": "renew", "date": "2018 10-01 12:33:23", "amount": "1m"},
    {"event": "buy", "date": "2019 03-01 12:33:23", "amount": "1m"},
    # {"event": "buy", "date": "2019 04-20 12:33:23", "amount": "0d"},
]

today = datetime.date.today()
yesterday = datetime.date.today() - datetime.timedelta(days=1)
days = {'0d': 0, '3d': 3, '1m': 30, '3m': 90, '6m': 180, '1y': 360}


def string2date(string_date):
    return datetime.datetime.strptime(string_date, "%Y %m-%d %H:%M:%S").date()


database = {
    'has_try': False,
    'expired_date': yesterday,
    'renew_deadline': yesterday,
}


def wrapper(fun):
    def _deco(event):
        fun(event)
        print(
            'premium:{} can_review:{} expired:{}'.format(is_premium(event), now_could_review(event),
                                                         is_expired_now(event)))

    return _deco


def is_premium(event):
    if database.get('expired_date') >= string2date(event['date']):
        return True
    return False


def expired_date():
    return database.get('expired_date')


def is_expired(event):
    return True if database.get('expired_date') <= string2date(event['date']) else False


def is_expired_now(event):
    return True if database.get('expired_date') <= today else False


def renew_deadline():
    return database.get('renew_deadline')


def could_review(event):
    return True if database.get('renew_deadline') > string2date(event['date']) else False


def now_could_review(event):
    return True if database.get('renew_deadline') > string2date(event['date']) else False


@wrapper
def event_try(event):
    if database.get('has_try'):
        print('this account had been tried 3d, try premium does not enjoy renew cut.')
    else:
        database.update({
            'has_try': True,
            'expired_date': string2date(event['date']) + datetime.timedelta(days=3),
            'renew_deadline': string2date(event['date']) + datetime.timedelta(days=3 + 15)
        })
        print('Try success, your expired date is {}'.format(database.get('expired_date')))


@wrapper
def event_buy(event):
    amount = event['amount']
    if could_review(event) is True:
        print('You have bean a premium, buy will extending premium')
        event_renew(event)
    else:
        database.update({
            'has_try': True,
            'expired_date': string2date(event['date']) + datetime.timedelta(days=days[amount]),
            'renew_deadline': string2date(event['date']) + datetime.timedelta(days=days[amount] + 15)
        })
        print('Buy success, your expired date is {}'.format(database.get('expired_date')))


@wrapper
def event_renew(event):
    amount = event['amount']
    _expired_data = database.get('expired_date')
    if could_review(event) is True:
        database.update({
            'has_try': True,
            'expired_date': _expired_data + datetime.timedelta(days=days[amount]),
            'renew_deadline': _expired_data + datetime.timedelta(days=days[amount] + 15),
        })
        print('Renew success, your expired date is {}'.format(database.get('expired_date')))
    else:
        print('This account has not bought premium, or over renew deadline, please buy premium as first')


def deal_event(event):
    choice_fun = {
        'try': event_try,
        'buy': event_buy,
        'renew': event_renew,
    }
    fun = choice_fun[event['event']]
    fun(event)


if __name__ == '__main__':
    [deal_event(event) for event in test_event]
    print(database)

实现类似视频网站订阅会员，并且有一定订阅优惠策略。
看完fluent python 决定用策略模式重构一遍。