Parsons Puzzles

Parsons Puzzles: Self-Test Your Python Skills

Parsons puzzles have been studied by Computing Education researchers in a variety of contexts.

Created by Dale Parsons and Patricia Haden in 2006 (ish), there have since been many research articles and educational resources related to Parson's puzzles.

http://mrschom.pythonanywhere.com/puzzle/all

Reference:
Parsons, D., & Haden, P. (2006, January). Parson's programming puzzles: a fun and effective learning tool for first programming courses. In Proceedings of the 8th Australasian Conference on Computing Education-Volume 52 (pp. 157-163). Australian Computer Society, Inc.