Tutorials · Chapter D (4/4) · ~10 min

Git basics

Try it → see it → read → next

Save meaningful snapshots of a project so you can inspect, compare, and recover your work.

Try yourself

Playground

Git time machine

Walk commit → branch → break → recover → PR — one step at a time.

1 / 5

→ 1. Make a commit
○ 2. Create a branch
○ 3. Break a file (oops)
○ 4. Recover with checkout / reset
○ 5. Open a PR

Stage a focused change and commit with a clear why.

Recap

What you just did

GitTimeMachine walked commit → branch → break → recover → PR. Local history is how you undo mistakes without rewriting shared remotes carelessly.

Teach

How it works

The everyday loop is:

git status
git diff
git add train.py README.md
git commit -m "Add held-out model evaluation"
git log --oneline

Working tree contains your current files
Staging area selects what the next commit includes
Commit stores a snapshot plus message
History lets you compare decisions over time

Mental model: Git is a project time machine with named, intentional checkpoints.

Use it

When you'd use this

Saving a working experiment before trying a risky change
Reviewing exactly what code changed
Collaborating without emailing folders named final-v7

Watch out

Git is not automatic backup until history exists somewhere else. Never commit API keys, credentials, private datasets, or a virtual environment. Review git diff and git status before each commit.

Try next

Try this next

Change one harmless line, inspect the diff, then restore it manually. Confirm git status returns to clean.