Creating an abstract base class
Imagine we are creating a media player with third-party plugins. It is advisable to create an abstract base class (ABC) in this case to document what API the third-party plugins should provide (documentation is one of the stronger use cases for ABCs).
The general design is to have a common feature, like play(), that applies to a number of classes. We don't want to pick some particular media format to use as a superclass; it seems somehow wrong to claim that some format is foundational, and all others are derived from it.
We'd prefer to define the media player as an abstraction. Each unique kind of media file format can provide a concrete implementation of the abstraction.
The abc module provides the tools to do this. Here's an abstract class that requires a subclass to provide a concrete method and a concrete property to be useful:
class MediaLoader(abc.ABC):
@abc.abstractmethod
def play(self) ->...
