Practice Arena

Python Coding
Challenges

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925 challenges 556 easy 323 medium 46 hard

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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

Python Basics easy

Boolean Mask Filter

Write a function that filters a list based on a boolean mask and returns the selected elements.

filter boolean lists

Strings & Text easy

Repeat each character n times

Given a string s and an integer n, return a new string where each character of s is repeated n times consecutively.

strings join comprehension

Lists & Arrays easy

Generate a Multiplication Table

Build a function that returns an n x n multiplication table as a list of lists.

nested-loops list-comprehension matrix

Lists & Arrays easy

Image channel swap

Implement a function that swaps the red and blue channels of an RGB image.

lists comprehensions rgb

Lists & Arrays easy

Cartesian Product Pairs

Create a function that returns the Cartesian product of two lists as a sorted list of lists.

lists tuples sorting

Lists & Arrays easy

Boolean Mask Filter

Write a function that filters a list using a boolean mask and returns the matching elements as a list.

mask filter list

Matrix & 2D Arrays easy

Flipping an Image

Implement a function that flips an image represented as a binary matrix by reversing each row and inverting each pixel.

matrix list-comprehension bitwise

Showing 1–7 of 7 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.