Middle node index
Return the floor middle index for a non-empty list.
Maximum node value
Return the largest integer or None when empty.
Remove the head node
Return a new list without the first node.
Rotate Image 90 Degrees Clockwise
Rotate a square matrix 90 degrees clockwise and return the rotated matrix.
Diagonal Traverse Matrix
Implement a function that returns all elements of a matrix in diagonal zigzag order.
Transpose Matrix In-Place
Implement a function that transposes a square matrix in-place and returns the transposed matrix.
Matrix Multiply 2D
Write a function that multiplies two 2D matrices (lists of lists) and returns the product matrix.
Transpose 2D Array
Implement a function that returns the transpose of a rectangular 2D list.
Days in month
Write a function that returns the number of days in a given month and year, correctly handling leap years.
Days Between Dates
Write a function that returns the number of days between two given dates.
Add Days to Date
Given a date in YYYY-MM-DD format and an integer number of days, return the resulting date in the same format.
Weekday from date
Write a function that returns the full English weekday name for a date string.
Leap Years in Range
Write a function that returns a list of all leap years between two given years, inclusive.
Age in years months days
Given birth and reference dates, return age as a dictionary with years, months, days.
Time Difference HH:MM
Given two times in HH:MM format, return the absolute difference as a string in HH:MM format.
Unix timestamp to datetime
Write a function that returns a UTC datetime string from a Unix timestamp.
Next Weekday Finder
Write a function that returns the next weekday date after a given date.
Previous Weekday Finder
Given a date, return the date of the immediately preceding weekday (Monday–Friday).
Week Number ISO
Given a date, return its ISO 8601 week number (1–53) without using datetime.isocalendar().
Schedule conflict check
Write a function that takes a list of time intervals and returns True if any two overlap.
Month End Date
Implement a function that returns the last day of the month for a given year and month.
Month Start Date
Parse a date string and return the first day of its month in the same format.
Parse email header
Write a function that parses a raw email header string and returns sender, recipient, and subject.
Inner Join Two Tables
Write a function that inner joins two lists of dictionaries on a common key and returns the combined rows.
Showing 217–240 of 255 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.