Practice Arena

Python Coding
Challenges

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

819 challenges 506 easy 280 medium 33 hard

All Easy Medium Hard

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

Strings & Text medium

Zigzag string conversion

Encode a string in zigzag order across numRows rows, then read row by row.

Greedy Algorithms medium

Minimum Number of Arrows to Burst Balloons

Given balloon intervals, find the minimum number of arrows to burst all balloons by merging overlaps.

greedy sorting intervals

Binary Search medium

Search 2D Matrix

Given a sorted 2D matrix with sorted rows and first element of each row greater than last of previous, find target efficiently.

binary search 2d matrix searching

SQL & SQLite medium

Index Creation Query

Create an in-memory SQLite database, execute CREATE INDEX statements, and return the resulting index metadata rows.

sqlite create-index schema

Showing 4 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.