Generator Pipeline
Implement a generator function that yields only even numbers from an input list, squared.
Range-like generator
Implement a custom generator that yields numbers like Python's range but with flexible bounds.
Fibonacci Generator
Create a generator function that yields Fibonacci numbers from 0 upward until a given limit.
File Line Reader Generator
Implement a generator function that reads a file-like object and yields each non-empty line without loading the whole file into memory.
Flatten Nested List Iterator
Implement a class that iterates over all integers in a nested list structure in depth-first order.
Iterator protocol class
Implement a class that follows the iterator protocol and yields squared numbers up to a given limit.
Cartesian Product Generator
Implement a generator function that yields the Cartesian product of multiple input iterables without precomputing all results.
Cached Property Manual
Implement a decorator that turns a method into a lazy cached attribute per instance.
Non-greedy quantifier
Implement a function that uses a non-greedy regex to extract the shortest substring between two delimiters.
Showing 1–9 of 9 challenges
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.