A easy Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

easy

Seniority

L3

Problem

Given a list of items (possibly with duplicates), return a new list containing only the first occurrence of each value, preserving input order.

Summary

Clean up duplicate events without losing the timeline.

Practice This Problem

Solve this Python problem with real code execution. DataDriven runs your Python code in a real environment and grades it automatically.