Abstract base classes in Python
Python interview exercise on Classes & Dataclasses, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write an abstract Shape with an abstract area() and a concrete describe() returning "<ClassName> with area <area to 1 decimal>". Then Square(side) and Circle(radius, using math.pi). Shape itself cannot be instantiated.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.