Min of three numbers
Write a function that returns the minimum of three integers.
Seconds to Hours Minutes Seconds
Convert total seconds into a zero-padded HH:MM:SS format.
Minutes to Hours: Time Conversion Helper
Write a function that converts minutes into a human-readable 'Xh Ym' string, with special cases for zero and whole hours.
Find Minimum Value
Write a function that returns the minimum integer from a given list.
Range of values
Calculate the range (max minus min) of a list of numbers. Empty list returns 0.
Condition Variable Waiter
Implement a deterministic simulation of a waiter whose tray has limited capacity and who becomes busy for a fixed time after each pickup.
Min-Max Scaler: Fit and Transform
Implement a MinMaxScaler class that normalizes numeric data to a given range using fit and transform methods.
Jump Game Minimum Jumps
Given an array of non-negative integers where each element is the maximum jump length, compute the minimum jumps to reach the last index.
Is pangram
Write a function that determines whether a given string is a pangram, ignoring case and non-letter characters.
Is isogram
Implement a function that determines whether a string is an isogram (no repeated letters, case-insensitive).
Is rotation of another string
Write a function to determine if one string is a rotation of another string.
Hamming Distance
Implement a function that computes the Hamming distance between two strings of equal length.
Minimum Remove Valid Parentheses
Given a string with parentheses and letters, remove the fewest parentheses to make it valid.
Parse bullet list
Parse a markdown-style bullet list and return the list of item texts, stripping bullet markers and trimming surrounding whitespace.
User Friendly Message
Given a raw user input, format it into a single clean sentence with proper sentence case and trimming.
Crawler Log Folder
Given a list of folder navigation operations, compute the minimum steps required to return to the main folder.
Average excluding min and max
Return the average of a list after discarding the lowest and highest elements, handling edge cases.
Partition Array
Implement a function that finds a contiguous partition of a list into k groups, minimizing the maximum sum of the groups.
Normalize Array to Zero-One Range
Implement a function that normalizes a list of numbers to the range [0,1] using min-max scaling.
Merge dicts summing values
Write a function that merges two dictionaries by summing values for duplicated keys.
Count Pairs with Sum
Implement a function that counts the number of distinct pairs in a list summing to a target.
Ransom Note Builder
Given two strings, determine if the ransom note can be formed from the words in the magazine.
Longest Harmonious Subsequence
Given a list of integers, find the length of the longest harmonious subsequence where the difference between maximum and minimum values is exactly 1.
Class Method Factory
Create a class method factory that dynamically adds methods to a class based on a mapping of names to behaviors.
Showing 1–24 of 148 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.