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Python Coding
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467 challenges 330 easy 120 medium 17 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

Pathlib Operations: File Path Basics

Practice using pathlib to manipulate file paths and extract components.

pathlib file-paths strings

Strings & Text easy

Stack Trace Sanitizer

Implement a function that rewrites traceback file paths to basenames only.

strings regex parsing

Strings & Text easy

Extract file extensions

Implement a function that extracts the extension from a filename according to standard rules.

strings parsing file-paths

Data Structures & Algorithms medium

Path Sum II All Paths

Return all root-to-leaf paths where the sum of node values equals a target.

binary-tree dfs backtracking

Dynamic Programming easy

Unique Paths in a Grid

Count the number of unique paths from the top-left corner to the bottom-right corner of a grid, moving only right and down.

dynamic-programming grid counting

Dynamic Programming medium

Unique Paths with Obstacles

Given a 2D grid with obstacles, count the unique paths from top-left to bottom-right moving only down or right.

dynamic-programming grid 2d-array

Graphs & Graph Algorithms medium

All Paths from Source to Target

Given a directed acyclic graph, return all paths from node 0 to the last node.

graph dfs backtracking

Showing 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.