From the website: https://adventofcode.com Advent of Code is an Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like. People use them as interview prep, company training, university coursework, practice problems, a speed contest, or to challenge each other.
The best description of Advent of Code I found came from the following article: https://auth0.com/blog/advent-of-code-tips-tricks/
Another good read and where I borrowed the utils.py from: https://hamatti.org/posts/tips-for-advent-of-code/