The Lazy Stream
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
- L5
Interview Prompt
Given a list that may contain some inner lists (one level of nesting), return a flat list where inner lists are expanded element-by-element in place. Strings count as leaves even though iterable. Do not recurse into deeper levels.
Summary
Yield values one at a time from a potentially infinite source.
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