Single Responsibility Principle

users_moderating.py

'''
https://twitter.com/jangiacomelli/status/1343676834085543936
'''

from datetime import datetime, timedelta
import logging

class User:

    def __init__(self, username):
        self.name = username

    def __repr__(self):
        return f'{self.__class__.__name__}({self.name!r})'

class UserRepository:
    
    def __init__(self, database):
        self.name = database

    def __repr__(self):
        return f'{self.__class__.__name__}({self.name!r})'

    def save(self, user):
        logging.info(f'Saving {user!r} to {self!r}')

class Moderator:

    def __init__(self, user_repository, default_penalty=7):
        self.repo = user_repository
        self.penalty = timedelta(days=default_penalty)

    def add(self, user):
        user.banned_until = None
        self.repo.save(user)
        logging.info(f'{user!r} added to {self.repo!r}')
    
    def ban(self, user):
        user.banned_until = datetime.today() + self.penalty
        logging.warning(f'{user!r} is banned until {user.banned_until:%B %d, %Y}')
        self.repo.save(user)

class Bookkeeper:

    def __init__(self, system):
        self.system = system

    def charge(self, user):
        logging.info(f'Charge credit card of {user!r} using {self.system}')


if __name__ == '__main__':
    logging.getLogger().setLevel(logging.INFO)
    users = UserRepository('PostgreSQL')
    logging.info(f'Connected to {users!r} at {datetime.today():%B %d, %Y}')
    moderator = Moderator(users)
    bookkeeper = Bookkeeper('Stripe')

    mike = User('Mike')
    logging.info(f'{mike!r} came in.')
    moderator.add(mike)
    bookkeeper.charge(mike)
    moderator.ban(mike)

https://twitter.com/testdrivenio/status/1338959747769307140