How to flag a method to be required to overload when inheriting in Python?

Question

I want to tell the future programmer the following class methods must be overridden if the AbstractCrawler is inherited.

class AbstractCrawler(object):

    def get_playlist_videos():
        pass

    def get_related_videos():
        pass

    def create_playlists():
        pass

Answer 1

You can mark the class and its methods as abstract:

from abc import ABC, abstractmethod

class AbstractCrawler(ABC):
    @abstractmethod
    def get_playlist_videos(self):
        pass

    @abstractmethod
    def get_related_videos(self):
        pass

    @abstractmethod
    def create_playlists(self):
        pass

Then:

class ImplCrawler(AbstractCrawler):
    pass

>>> i = ImplCrawler()
Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: Can't instantiate abstract class ImplCrawler with abstract methods create_playlists, get_playlist_videos, get_related_videos

Compared to:

class ImplCrawler(AbstractCrawler):
    def get_playlist_videos(self):
        pass

    def get_related_videos(self):
        pass

    def create_playlists(self):
        pass

>>> i = ImplCrawler()
# No error