Practice Arena

Python Coding
Challenges

Write real Python in the browser. Instant feedback. From beginner to expert.

925 challenges 556 easy 323 medium 46 hard

All Easy Medium Hard

All Python Basics Strings & Text Lists & Arrays Dicts & Sets Functions & Closures OOP & Classes Data Structures & Algorithms Advanced Python Iterators & Generators Decorators & Context Managers Error Handling & Exceptions Regular Expressions Math & Number Theory Bit Manipulation Dynamic Programming Trees & Binary Trees Graphs & Graph Algorithms Recursion & Backtracking Greedy Algorithms Binary Search Two Pointers & Sliding Window Stacks & Queues Heaps & Priority Queues Linked Lists Matrix & 2D Arrays Datetime & Time Calculations Data Formats & Parsing SQL & SQLite Numpy & Vectorized Computing Cryptography & Hashing

Advanced Python medium

2D Vector dataclass

Implement a Vector2D dataclass with +, -, scalar *, dot product, and magnitude.

dataclass OOP math

Advanced Python hard

Data pipeline

Implement a Pipeline class supporting pipe chaining with the | operator.

functional OOP pipeline

Advanced Python hard

Validated descriptor

Implement a TypedField descriptor that raises TypeError if the value is not of the expected type.

descriptors OOP metaclass

Advanced Python medium

Metaclass Registry

Implement a metaclass that automatically registers every subclass in a class-level registry.

metaclass registry oop

Advanced Python medium

Descriptor Property

Create a descriptor class that ensures attribute values are positive integers.

descriptors oop python-advanced

Error Handling & Exceptions easy

Validation result object

Implement a ValidationResult class that tracks validation errors and can report validity.

validation error-handling oop

Math & Number Theory easy

Sieve of Eratosthenes

Implement the Sieve of Eratosthenes to return a sorted list of all primes up to a given integer n.

primes sieve loops

Math & Number Theory easy

Prime Factorization

Return a sorted list of prime factors of a positive integer, including repeated factors.

prime math loops

Math & Number Theory easy

Happy number check

Implement a function that returns True if a number is happy, False otherwise.

Greedy Algorithms medium

Gas Station Circuit

Given gas and cost arrays for a circular route, determine the starting gas station index that allows a full loop, or -1 if none exists.

greedy arrays circular

Matrix & 2D Arrays easy

Matrix Multiply 2D

Write a function that multiplies two 2D matrices (lists of lists) and returns the product matrix.

matrix multiplication nested-loops

Showing 49–59 of 59 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.