Condition Variable Waiter
Implement a deterministic simulation of a waiter whose tray has limited capacity and who becomes busy for a fixed time after each pickup.
Safe Command Executor
Implement emulate_run that simulates running a command list and returns output and exit code.
Crawler Log Folder
Given a list of folder navigation operations, compute the minimum steps required to return to the main folder.
Lemonade Change
Simulate a lemonade stand and decide if you can provide change for each customer using only $5, $10, and $20 bills.
Last Stone Weight
Given an array of stone weights, repeatedly smash the two heaviest stones and return the last remaining weight or 0.
Showing 1–5 of 5 challenges · easy
Guide: free Python coding challenges
Practice Python by solving problems
PythonSkillset challenges are hands-on coding exercises from beginner to advanced. Open a challenge, read the problem, write Python in the split-pane editor, and run tests with Pyodide — no install required.
How to use the arena
- Pick a category — basics, algorithms, strings, and more
- Open a challenge, read the statement, and edit the starter code
- Run tests, fix failures, then try a related quiz or tutorial lesson
Challenges vs tutorials and quizzes
Challenges test what you can build under constraints. For guided teaching, use our Python tutorials. For quick checks, try quizzes or copy snippets from code samples.