Data Structures & Algorithms in Python

Data structures and algorithms are the skills that separate someone who can write Python from someone who can engineer with it, and they are the backbone of nearly every technical interview at serious software companies. This free course teaches DSA the way it should be taught: by running real code. Every lesson includes live Python playgrounds that execute in your browser, plus graded exercises with hints and solutions, so you never just read about an algorithm, you run it, time it, break it, and fix it. You can even expand any editor to a fullscreen IDE while you work.

Across four modules you will build the complete toolkit. You start with Big-O notation and learn to measure complexity in real milliseconds, then look inside Python lists to understand why some operations are instant and others quietly scan thousands of items. From there you implement the core structures by hand: stacks, queues with deque, linked lists built from nodes and pointers, and the hash tables behind dict and set. The algorithms module covers recursion and memoization, linear and binary search, and the classic sorts from bubble to merge to quicksort, always compared against Python's own Timsort. You finish with binary search trees, graph traversal with BFS and DFS, and the two-pointer and sliding-window patterns that crack most interview questions.

No paid tools and no setup are required, everything runs in your browser, and you earn a free certificate by passing the final exam. If you know basic Python syntax (variables, loops, functions), you are ready. If you need a refresher first, our Interactive Python Practice course covers the prerequisites, and our JavaScript DSA course makes a great follow-up if you work across both languages.