Boolean Mask Filter
Write a function that filters a list based on a boolean mask and returns the selected elements.
Map, Filter, Reduce
Implement three functions using map, filter, and reduce to manipulate a list of integers.
Filter by Age
Filter a list of person dictionaries by age and return their names.
Logging Filter
Given a list of log entries, return those matching a given severity level and containing a keyword.
Remove Duplicates from String
Given a string, return a new string with each character that repeats consecutively reduced to a single occurrence.
Extract digits from string
Write a function that extracts all digit characters from a given string, preserving their original order.
Boolean Mask Filter
Write a function that filters a list using a boolean mask and returns the matching elements as a list.
Values that appear once
Return a list of numbers that appear exactly once in the input list, in original order.
Delete Old Records
Filter a list of records by removing those with a date older than a given cutoff date.
Generator Pipeline
Implement a generator function that yields only even numbers from an input list, squared.
Leap Years in Range
Write a function that returns a list of all leap years between two given years, inclusive.
Showing 1–11 of 11 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.