The Column Transformer
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
- L3
Interview Prompt
An ETL step ships its per-column transforms as configuration: `transforms` maps a column name to the name of an operation, while `rows` is a list of same-keyed dicts. An operation is one of `'upper'` or `'lower'` to change a string's case, `'increment'` to add one to a number, or `'double'` to multiply a number by two. Apply each column's operation to its value in every row and return the updated rows.
Summary
Each column gets its function.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your Python against test cases
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision