Chunk a list into n-sized parts
Write a function that divides a list into sublists of at most n elements.
Rotate Left by k
Implement a function that rotates a list left by k positions.
Interleave Two Lists
Write a function that interleaves two lists element by element, preserving order.
Running Maximum
Implement a function that returns a list where each element is the largest value seen so far.
Insert into a Sorted List
Implement a function that inserts a value into a sorted list at the correct position using binary search.
Zip lists into pairs
Write a function that takes two lists and returns a list of two-element sublists pairing elements by index up to the shortest length.
Middle Element of an Odd-Length List
Implement a function that returns the middle element of an odd-length list.
Is Subset of Another List
Write a function that returns True if every element in a given list exists in another list, ignoring duplicates.
Unzip pairs into two lists
Write a function that takes a list of pairs and returns two separate lists: first elements and second elements.
Generate a Multiplication Table
Build a function that returns an n x n multiplication table as a list of lists.
Majority Element Finder
Implement a function that returns the majority element in a list, which appears more than half the time.
Union of Two Lists
Implement a function that combines two lists and returns only unique elements.
Difference of Two Lists
Write a function that returns items in list a that are not in list b, preserving order and duplicates.
Chunk list into groups
Implement a function that splits a list into sublists of a given size.
Zip Two Lists
Write a function that pairs elements from two lists by index, stopping at the shorter list.
Rearrange Positives and Negatives
Write a function that rearranges a list in-place so all negative numbers come before non-negative numbers.
Last occurrence index
Implement a function that returns the last index of a given value in a list, or -1 if the value is not present.
Image channel swap
Implement a function that swaps the red and blue channels of an RGB image.
Pad Array Edges
Write a function that pads a list with zeros on both ends.
Merge Sorted Array In Place
Write a function that merges two sorted arrays into the first array in-place, keeping the result sorted.
Cartesian Product Pairs
Create a function that returns the Cartesian product of two lists as a sorted list of lists.
Sort List Merge Sort
Write a function that sorts a list of integers using the merge sort algorithm.
Rotate List Right by k
Implement a function that rotates a list to the right by k positions.
Running Total Window
Implement a function that returns a list of running totals, resetting to zero after each positive sum.
Showing 1–24 of 29 challenges · easy · Lists & Arrays
Lists & Arrays — Python coding challenges
What you will find here
This page lists lists & arrays challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.
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.