What is the diamond problem in multiple inheritance?
PICTURE THIS: OOP PILLARS
Simple meaning
A diamond occurs when two bases share a common ancestor, so a method could be inherited twice.
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:
- 1A diamond occurs when
two bases share a common ancestor, so a method could be inherited twice.
- 2C3 MRO visits each
class once in a consistent order, and super() along that chain avoids double initialization if everyone cooperates.
- 3Without super(), the ancestor's
__init__ may run twice or not at all.
- 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
A diamond occurs when two bases share a common ancestor, so a method could be inherited twice. C3 MRO visits each class once in a consistent order, and super() along that chain avoids double initialization if everyone cooperates.