For this module, close Copilot Chat. Everything here is done with buttons in VS Code, so you understand each step yourself.
8.1 Git in plain words
In a video game you save before the boss fight, and reload if you lose. Git does that for your project. It is a free tool on your laptop that keeps a history of your files.
| Word | Meaning |
|---|---|
| Repository (repo) | Your project folder, plus its full history of save points |
| Stage | Choosing which changed files go into the next save point |
| Commit | One save point, with a short message saying what changed |
| GitHub | A website that keeps an online copy of your repository |
| Push | Uploading your commits from your laptop to GitHub |
Why it matters today: Streamlit Community Cloud takes your app from GitHub. No push, no live app.
8.2 Before your first save: check .gitignore and tell Git who you are
Do it
Open .gitignore in the Explorer. Check that it has a line that says .env. This tells Git never to save your key file. If the line is missing, add it and save the file.
Git writes your name on every commit, so it needs to know who you are. Open the terminal, stop the app with Ctrl+C, and run these two commands, one at a time, with your own name and the email of your GitHub account:
git config --global user.name "Your Name"
git config --global user.email "you@example.com"
Nothing appears when they succeed. You only do this once per laptop.
8.3 Create the repository
Do it click the Source Control icon in the left bar (Ctrl+Shift+G). Because your folder is not a repository yet, you see a button Initialize Repository. Click it.
the panel now lists your files under Changes, each with a U (untracked: Git sees it, but has not saved it yet). .env is not in the list, and in the Explorer its name is greyed out. That is .gitignore at work. If .env is in the list, stop and tell a mentor.
8.4 Make your first commit
Do it
Hover over the Changes heading and click the + (Stage All Changes). The files move up to Staged Changes.
In the box above, type a short note on what this save point holds, for example Investment calculator with live IDX prices.
Click Commit.
the Changes list is empty: everything is saved in a commit on your laptop. Nothing is on the internet yet.
8.5 Push to GitHub
Do it
In Source Control, click Publish Branch.
If VS Code asks you to sign in to GitHub, allow it, and approve in the browser window that opens.
Choose Publish to GitHub public repository. Keep the suggested name or type your own, such as idx-stock-snapshot.
Wait for the message that the repository was published, and click Open on GitHub.
on github.com you see your files, including app.py and requirements.txt, and your commit message. .env must not be there. If it is, tell a mentor: the key must be replaced, because deleting the file still leaves it in the history.
8.6 The everyday flow
From now on, every time your app works a little better:
| Step | In Source Control |
|---|---|
| 1. Stage | + next to Changes |
| 2. Commit | Type a message that says what changed, click Commit |
| 3. Push | Click Sync Changes to upload your new commits to GitHub |
Save often: a commit is cheap, and it is your way back. If a later change breaks your app, right-click a file under Changes → Discard Changes, and that file goes back to your last commit. This cannot be undone.