Practice Arena

Python Coding
Challenges

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925 challenges 556 easy 323 medium 46 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

Python Basics easy

Insert New Row

Implement a function that inserts a new row into a 2D list at a specified index.

lists insert rows

Lists & Arrays easy

Insert into a Sorted List

Implement a function that inserts a value into a sorted list at the correct position using binary search.

lists binary-search insertion

Lists & Arrays easy

Insertion Sort

Implement insertion sort that sorts a list in-place and returns the same list.

sorting in-place algorithms

Data Structures & Algorithms medium

Bucket Sort

Implement bucket sort to sort a list of floating-point numbers in the range [0,1).

sorting bucket-sort insertion-sort

Data Structures & Algorithms easy

Shell Sort

Implement Shell sort, an in-place comparison sort that generalizes insertion sort, using a gap sequence that shrinks by half each pass.

sorting shell-sort in-place

Data Structures & Algorithms medium

Trie Insert and Search

Implement a Trie and a scenario runner that executes insert/search/prefix operations.

trie insert search

Data Structures & Algorithms medium

Design Skip List Lite

Implement a simplified skip list supporting insert, search, and delete with O(log n) average complexity.

skip-list linked-list search

Trees & Binary Trees easy

Insert into BST

Implement insertion into a Binary Search Tree while maintaining BST properties.

binary-search-tree recursion tree

Greedy Algorithms medium

Queue Reconstruction by Height

Given shuffled pairs of (height, number_of_taller_people_in_front), reconstruct the original queue order.

greedy sorting insertion

Binary Search easy

Search Insert Position

Return the index where a target should be inserted into a sorted list to maintain order.

binary-search arrays searching

Linked Lists medium

Prepend a new head

Insert value at the front of the list.

linked-list lists pointers

Linked Lists hard

Insert value at index

Insert x at index i in a new list.

linked-list lists pointers

SQL & SQLite easy

Add column alter

Write a function that connects to an in-memory SQLite database, creates a table, inserts rows, and adds a new column with ALTER TABLE.

sqlite alter-table ddl

Showing 1–13 of 13 challenges

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.