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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

Data Structures & Algorithms medium

Find Peak Element

Implement a function that returns the index of any peak element in an integer array.

arrays search binary-search

Data Structures & Algorithms medium

Merge Sort

Implement merge_sort(numbers) that returns a sorted copy of the input list using the merge sort algorithm.

sorting recursion divide-and-conquer

Dynamic Programming medium

Kadane Variant: Maximum Product Subarray

Implement max_product_subarray(nums) that returns the maximum product of any contiguous subarray.

kadane subarray product

Trees & Binary Trees medium

Delete Node in BST

Implement a function that deletes a key from a binary search tree and returns the new root.

binary-search-tree tree-traversal recursion

Graphs & Graph Algorithms medium

Articulation Points

Implement a function that returns the articulation points of an undirected graph.

graphs dfs bridges

Graphs & Graph Algorithms medium

Bridges in Graph

Implement a function that returns all bridges in an undirected graph.

graph dfs bridges

Recursion & Backtracking medium

Combination Generator

Write a recursive function that returns all combinations of length k from a list of distinct integers.

recursion backtracking combinations

Showing 7 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.