Practice Arena

Python Coding
Challenges

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

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

Lists & Arrays easy

Remove duplicates (sorted)

Return a sorted list with duplicates removed.

arrays two-pointer

Lists & Arrays easy

Merge two sorted arrays

Merge two sorted arrays into one sorted array.

arrays merge two-pointer

Lists & Arrays easy

Move Zeros to the End

Reorder a list in-place, pushing all zeros to the end while preserving the order of non-zero numbers.

lists in-place two-pointer

Lists & Arrays medium

Partition around a pivot value

Implement an in-place partition of a list around a given pivot value, returning the boundary index.

lists partition two-pointer

Lists & Arrays easy

Move Zeros to End

Rearrange a list by moving all zeros to the end while preserving the relative order of non-zero elements.

list in-place two-pointer

Lists & Arrays easy

Rearrange Positives and Negatives

Write a function that rearranges a list in-place so all negative numbers come before non-negative numbers.

in-place two-pointers partition

Showing 6 challenges · Lists & Arrays

Lists & Arrays — Python coding challenges

What you will find here

This page lists lists & arrays challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.

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.