What are abstract base classes in Python?
PICTURE THIS: DJANGO MVT
Simple meaning
ABCs, from abc.ABC, let you declare abstract methods that subclasses must implement.
WHY — OOP instead of guessing?
Why interviewers care about OOP:
who only read docs from people who shipped.
and tied to Python work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1ABCs, from abc.ABC, let
you declare abstract methods that subclasses must implement.
- 2They can also register
virtual subclasses without inheritance.
- 3Django's forms and DRF's
views are not ABCs in the stdlib sense, but the same idea shows up in interface-style APIs.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
ABCs, from abc.ABC, let you declare abstract methods that subclasses must implement. They can also register virtual subclasses without inheritance.