Left Join
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
- L4
Interview Prompt
Given two lists of dicts (left, right) and a shared key name, left-join the lists: for each left record, find the matching right record (the first one whose key matches) and merge its fields into the left record. If no right-side match exists, keep the left record as-is with no extra keys. Return the list.
Summary
Keep the left side. Match what you can.
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