Pathlib Operations: File Path Basics
Practice using pathlib to manipulate file paths and extract components.
Stack Trace Sanitizer
Implement a function that rewrites traceback file paths to basenames only.
Extract file extensions
Implement a function that extracts the extension from a filename according to standard rules.
Simplify Path
Implement a function that simplifies a Unix-style absolute file path to its canonical form.
Change directory manager
Implement a function that processes `cd` commands and returns the resulting absolute path.
Parse path segments
Implement a function that parses a path string into clean segments, ignoring slashes, empty parts, and dot segments.
Nested get with dotted path
Implement a function that safely retrieves a value from a deeply nested dictionary using a dot-separated path, returning a default if any key is missing.
Union Find Class
Implement a UnionFind class with find and union operations supporting path compression and union by size.
Path Sum II All Paths
Return all root-to-leaf paths where the sum of node values equals a target.
Reconstruct Itinerary
Given a list of airline tickets, reconstruct the itinerary in order using each ticket exactly once, choosing the lexicographically smallest path when multiple options exist.
Shortest Path in Binary Matrix
Implement BFS to find the shortest path length from (0,0) to (n-1,n-1) in an n x n binary matrix, moving through 0 cells in 8 directions.
Eulerian Path Check
Given the number of vertices and an edge list of an undirected graph, decide if it has an Eulerian path.
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.
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.
Triangle Minimum Path
Compute the minimum path sum from top to bottom of a triangle given as a list of lists.
Unique Paths in a Grid
Count distinct paths in an m x n grid moving only down or right.
Cherry Pickup Maximum
Given a grid with cherries, find the maximum cherries you can collect using two paths from top-left to bottom-right.
Minimum Falling Path Sum
Compute the minimum falling path sum in an n x n matrix by moving down or diagonally each step.
Minimum Path Sum Matrix
Implement a function that computes the minimum path sum from the top-left to the bottom-right of a grid moving only right or down.
Dungeon Game Minimum Health
Compute the minimum initial health needed to reach the bottom-right corner of a dungeon grid without health dropping to zero or below.
Sum Root to Leaf Numbers
Given the root of a binary tree, compute the total sum of all root-to-leaf numbers.
Dijkstra Shortest Path
Implement Dijkstra's algorithm on a weighted graph to return distances from a source to every node.
Bellman-Ford Algorithm
Implement the Bellman-Ford algorithm to compute shortest distances from a source in a directed weighted graph with up to 100 vertices and negative edges.
A* Pathfinding Heuristic
Implement A* search on a 2D grid to find the shortest path length between two cells.
Showing 1–24 of 31 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.