Set symmetric difference
Write a function that returns the elements found in exactly one of two sets, sorted ascending.
Is pangram
Write a function that determines whether a given string is a pangram, ignoring case and non-letter characters.
Extract mentions
Extract unique @mentions from a string, respecting email-like patterns and punctuation.
Is Subset of Another List
Write a function that returns True if every element in a given list exists in another list, ignoring duplicates.
Intersection two lists length
Return the number of distinct elements that appear in both input lists.
List intersection
Return the sorted list of elements common to both lists.
Union of Many Sets
Implement a function that takes any number of sets and returns a sorted list of their union.
Anagram Groups by Size
Group a list of words into anagram groups and return them sorted by group size and lexicographically.
Set intersection size
Count how many distinct values appear in both of two given lists.
Symmetric Difference
Write a function that computes the symmetric difference of two lists, returning a sorted list of unique elements.
Disjoint Set Check
Check if two lists are disjoint by verifying they have no common elements.
Subset of another set
Write a function that checks if every element of one set is contained in another.
Context Manager Class
Implement a context manager class that measures execution time and sets duration, with None if an exception occurred.
Power set size
Compute the size of the power set of a given sequence.
Set kth Bit
Implement a function that sets the kth bit (0-indexed) of a non-negative integer to 1 and returns the result.
Subset XOR sum
Given a list of integers, compute the bitwise XOR of each non-empty subset and return the sum of those XOR totals.
Clique Detection
Given an undirected graph and a list of vertices, check if every pair of distinct vertices in the list is connected by an edge.
Power set from set
Write a function to return the power set of a given list of distinct elements.
Showing 1–18 of 18 challenges · easy
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.