* Pyupgrade to Python 3.9 * updating DIRECTORY.md Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
* Added solution for Project Euler problem 74. Fixes: #2695 * Added doctest for solution() in project_euler/problem_74/sol1.py * Update docstrings and 0-padding of directory name. Reference: #3256