Split module into multiple files

__init__.py

from .social_media_post import SocialMediaPost
from .social_media_post_publisher import SocialMediaPostPublisher

# This is used by 'from socsocial_media_post import *'
# As far as there is nothing else here and in app.py
# we import the classes explicitely, this part can be ommited
__all__ = [
    'SocialMediaPost',
    'SocialMediaPostPublisher'
]

app.py

from social_media_post import (
    SocialMediaPost,
    SocialMediaPostPublisher,
)

post = SocialMediaPost('Hey guys!')
# NOTE: here SocialMediaPostPublisher is identified by media, not by post
publisher = SocialMediaPostPublisher(['Facebook', 'Twitter'])
publisher.publish(post)

facebook.py

class Facebook:
    # See notes for Twitter
    def publish(self, post):
        print(f'Publish on Facebook via its API: {post.content}')

linkedin.py

class LinkedIn:
    # See notes for Twitter
    def publish(self, post):
        print(f'Publish on Linkedin via its API: {post.content}')

make_project_structure.py

''' NOTE: gist.github.com does not allow directory creation.
Helper to make a social_media_post directory and move there files,
derived from social_media_post.py
'''
from pathlib import Path

module_folder = Path('social_media_post')
module_folder.mkdir()
files = [
    '__init__.py',
    'twitter.py',
    'facebook.py',
    'linkedin.py',
    'social_media_post_publisher.py',
    'social_media_post.py',
]
files = [Path(file) for file in files]

for file in files:
    file.replace(module_folder/file)

social_media_post.py

class SocialMediaPost:

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

social_media_post_publisher.py

# We import media locally, so we can reduce social_media_post.media to .media
from .twitter import Twitter
from .facebook import Facebook
from .linkedin import LinkedIn

PLATFORMS = {
    'Twitter': Twitter(), 
    'Facebook': Facebook(),
    'LinkedIn': LinkedIn()
}

class SocialMediaPostPublisher:

    def __init__(self, platforms):
        # The publisher is defined by the media, it has access to, not by a post
        if any(name not in PLATFORMS for name in platforms):
            raise Exception(f'Not all provided platforms are supported.')
        self.platforms = platforms

    def publish(self, post):
        for name in self.platforms:
            PLATFORMS[name].publish(post)

twitter.py

class Twitter:

    # NOTE: see for the opportunity to use a metaclass to force derived classes
    #       explicitly declare the publish method
    def publish(self, post):
        # TODO: replace 'Twitter' with self.__class__.__name__
        print(f'Publish on Twitter via its API: {post.content}')

1. download
2. unzip
3. run python make_project_structure.py
4. run python app.py

See code on github
See original tweet