Lesson 2 — The computing substrate: hardware, operating system, files, processes
Unit I · Substrate and mechanism

L02_my_machine.py                            student     Prints OS, Python version, CPU count, disk total/free and the folder it runs in.
L02_busy.py                                  student     Keeps one core busy with a countdown (15 s default) so you can find it as a process.

Python 3.11 or newer. Standard library only. Run each program from the folder the lesson tells you to put it in:
    python <file>.py        (Windows)
    python3 <file>.py       (macOS and Linux)
