Insert New Row
Implement a function that inserts a new row into a 2D list at a specified index.
Broadcast Add Scalar
Add a scalar to every number in a 2D list and return a new 2D list without modifying the original.
Fancy Index Select
Given a 2D matrix and a list of row indices, select those rows in order and return them as a new 2D list.
Reshape array dimensions
Implement a function that reshapes a 1D list into a 2D list with given dimensions.
Concatenate Horizontally
Write a function that horizontally concatenates two 2D lists into a new 2D list.
Dataclass with slots
Implement a slotted frozen dataclass representing a 2D point with total ordering.
Toeplitz Matrix Check
Write a function is_toeplitz(matrix) that checks if a 2D list is a Toeplitz matrix, where all elements on the same diagonal from top-left to bottom-right are identical.
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.
Showing 10 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.