The Lone Character

An easy Python mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.

Domain
Python
Difficulty
easy
Seniority
L5

Interview Prompt

We're scanning a stream of single-character event codes packed into one string. Return the first code that appears exactly once in it.

Summary

It appeared exactly one time. That made it special.

How This Interview Works

  1. Read the vague prompt (just like a real interview)
  2. Ask clarifying questions to the AI interviewer
  3. Write and run your Python against test cases
  4. Answer the interviewer's follow-up questions, then get a hire or no-hire decision