The Map Reducer
A medium Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- medium
- Seniority
- L3
Interview Prompt
Given a list of values, a mapper (single-arg function or lambda source string), and a reducer (two-arg function or lambda source string), apply mapper to each value, then reduce left-to-right with reducer. Return the final reduced value, or None if values is empty. If mapper or reducer is a string, eval it into a callable first.
Summary
Map it. Reduce it. One answer.
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