🏆Capstone project: Run the Durable Journal

The program is complete. This final lesson changes the surface, not the code: the panel below is a Bash session looking at the same saved chapter workspace.

Start by proving where you are and running the entry file twice:

pwd
python reading_log.py
python reading_log.py

Each successful run should print:

Wrote reading_report.txt and recorded 4 books.

Running it twice is not the interesting part. What the two runs leave behind is.

Inspect the durable result

cat reading_report.txt
cat reading_history.txt

The report should contain one current snapshot:

Reading report
==============
Books: 4
- The Left Hand of Darkness
- Cien años de soledad
- Piranesi
- Convenience Store Woman

The history should contain at least two complete Recorded 4 books. lines. If an earlier editor Run already created a record, it stays too. That is correct: the file exists to preserve successful runs, and this lesson does not pretend it began empty.

If the report contains two headings, revisit write_report: the snapshot was appended. If history contains only one line after two more runs, revisit append_history: earlier records were replaced. If Python cannot find data/books.txt, compare pwd with the project root before editing any path.

What you actually built

Press Check my work when the visible files agree.

Then look at the folder as a whole, because this is the first time in the course that all four pieces exist at once. There is a program, the input it reads, the current answer it produced, and a record of every time it ran. The Python process has exited. The terminal session will end. All four files are still there.

That is what “durable” means, and it is the difference between a program that computes something and a program that leaves something behind. Every project in the rest of this course is a variation on this shape.