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

Matrix & 2D Arrays medium

Shift 2D Grid

Implement a function to shift a 2D grid right by k positions, flattening the grid and wrapping elements.

grid list modulo

Matrix & 2D Arrays medium

Matrix Block Sum

Given a 2D matrix and a block size, compute the sum of each block centered at every cell.

matrix prefix-sum 2d-array

Matrix & 2D Arrays easy

Transpose Matrix In-Place

Implement a function that transposes a square matrix in-place and returns the transposed matrix.

matrix transpose in-place

Matrix & 2D Arrays medium

Word Search Matrix

Given a 2D board and a word, determine if the word can be formed by sequentially adjacent cells (horizontally or vertically), without reusing cells.

matrix dfs strings

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

Matrix & 2D Arrays easy

Transpose 2D Array

Implement a function that returns the transpose of a rectangular 2D list.

matrix transpose nested-lists

Showing 25–30 of 30 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.