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Python Coding
Challenges

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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

Data Structures & Algorithms medium

Coin change (DP)

Find the minimum number of coins to make exactly the target amount.

Dynamic Programming medium

Edit Distance (Levenshtein Distance)

Implement the classic edit distance algorithm to find the minimum number of single-character edits required to transform one string into another.

dynamic-programming strings levenshtein-distance

Dynamic Programming medium

Coin Change Minimum

Given coin denominations and a target amount, compute the minimum number of coins needed or -1 if impossible.

dynamic-programming coins minimum

Dynamic Programming medium

Paint House Colors

Given a cost matrix, compute the minimum total cost to paint all houses with no two adjacent houses having the same color.

dynamic-programming optimization arrays

Graphs & Graph Algorithms medium

Network Delay Time

Given a directed weighted graph and a starting node, find the minimum time for a signal to reach all nodes, or -1 if unreachable.

dijkstra shortest-path graph

Matrix & 2D Arrays medium

Rotting Oranges Time

Given a grid of fresh, rotten, and empty cells, compute the minimum minutes until all fresh oranges rot, or -1 if some are unreachable.

bfs grid simulation

Showing 6 challenges · medium

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.