os.path.join (folder, filename) ensures the path is correct for the system. On Windows, it uses backslashes (reports\summary.txt); on Linux and macOS it uses forward slashes (reports/summary.txt).

From the earliest year of school, children begin learning how to express ideas in different ways. Lines across a page, a wobbly letter, or a simple drawing form the foundation for how we share meaning ...

Physics and Python stuff. Most of the videos here are either adapted from class lectures or solving physics problems. I really like to use numerical calculations without all the fancy programming ...