Practice Arena

Python Coding
Challenges

Write real Python in the browser. Instant feedback. From beginner to expert.

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

Math & Number Theory medium

Binomial Coefficient

Implement a function to compute binomial coefficients modulo 10^9+7 for n up to 10^5.

modular-arithmetic combinatorics dynamic-programming

Bit Manipulation medium

Divide using shifts

Implement division of two integers using only bit shifts and arithmetic, without using division or modulo operators.

integer division bit shifts overflow

Stacks & Queues medium

Sum of Subarray Minimums

Given an integer array, sum the minimum of all contiguous subarrays modulo 10^9+7.

stack array monotonic-stack

Linked Lists medium

Rotate list left by k

Move the first k nodes to the end (k may exceed length; use modulo).

linked-list lists pointers

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

Showing 1–5 of 5 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.