Types, then the report, with notes of its own

This walk takes the end of tally. It adds types and a docstring, and then the report. It begins where tally counts, and has its tests, ruff and a corpus.

There are two ways to read this tutorial. Both have the same parts, in the same order.

Each part ends with a section called What changed. It lists every file that the part changes, with a link to the file, and then the whole diff of each file, folded. A lockfile and a binary file have a link alone. The text above it explains the change. In Build it yourself, What changed is what you check your files against.

In Build it yourself, a file that a command makes says which command. A diff that is open is a patch. Apply it with the command in the text, or make the same change in your editor.

Read the tutorial

Each change explained, with the code to look at.

Build it yourself

Every command to run and every change to make by hand, to make the project yourself.

Get the project

You build the project in a clone of your own, on a branch mine that starts where this walk starts. Run the commands of these pages in its top folder.

git clone https://github.com/rahuldave/tally
cd tally
git switch -c mine 1568a522d233

Then add the command git check, which compares your files with the project's after each move, and leaves what git add has staged as it was.

git config alias.check '!f() { i="$(git rev-parse --git-path check-index)" && { cp -p "$(git rev-parse --git-path index)" "$i" 2>/dev/null || rm -f "$i"; } && export GIT_INDEX_FILE="$i" && git add -A && git diff --cached --stat "$1"; }; f'

The parts