Why do you check data types during EDA?
PICTURE THIS: PYTHON TYPES
Simple meaning
Wrong types break aggregations: IDs stored as floats, dates as strings, or categories as integers that get averaged.
WHY — EDA instead of guessing?
Why interviewers care about EDA:
on EDA.
the situation, the default choice, and one exception - that reads as experience.
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:
- 1Wrong types break aggregations:
IDs stored as floats, dates as strings, or categories as integers that get averaged.
- 2Type checks also reveal
parsing issues such as mixed currencies in a numeric column.
- 3Casting early prevents silent
errors in groupby and joins.
- 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
Wrong types break aggregations: IDs stored as floats, dates as strings, or categories as integers that get averaged. Type checks also reveal parsing issues such as mixed currencies in a numeric column.