The Gaps Between
A hard Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- hard
- Seniority
- L4
Interview Prompt
A data-quality job profiles raw record exports before they load into the warehouse, and the records are dicts that don't all carry the same columns. For every column that appears in any record, report how many records hold a real value versus how many are blank, where blank means the value is `None` or the column is absent from that record entirely. Each column maps to its own `null_count` and `non_null_count`, and an empty batch produces an empty result.
Summary
The data is not as clean as it looks.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your python solution with real code execution
- Get instant feedback and a hire/no-hire decision