Git and GitHub

The idea

Git records snapshots of your project called commits. Each commit stores what changed, who changed it, when, and a message saying why. You can always go back to any snapshot. GitHub is a website that stores a copy of your commits online, so your work is backed up and recruiters can see it.

A file you change moves through three places:

code

working folder  --git add-->  staging area  --git commit-->  local history  --git push-->  GitHub

(your edits)                  ("include this")               (snapshot saved)             (online copy)

The staging area lets you choose which changes go into the next snapshot, so one commit can be "fix the total bug" even if you also edited another file.

One-time setup

bash

git config --global user.name "Priya Sharma"

git config --global user.email "[email protected]"   # use the same email as your GitHub account

To push to GitHub from the terminal you need to log in once. The easiest way is the GitHub CLI: install gh (cli.github.com), then run gh auth login and follow the prompts.

The everyday loop

Git's working directory, staging area, local repository and GitHub

Figure 1.2: Git's everyday loop: edit → git add (stage) → git commit (snapshot) → git push (share). git pull brings others' work back.

bash

git init                              # start tracking this folder (run once per project)

git status                            # what has changed? (run this constantly)

git add main.py                       # stage one file   (or `git add .` for everything)

git commit -m "Add expense menu"      # save the snapshot locally

git log --oneline                     # see your history

To publish the project on GitHub for the first time:

bash

gh repo create expense-tracker --public --source=. --push

After that, publishing new commits is just git push.

commit saves a snapshot on your laptop. push uploads your commits to GitHub. If you commit but never push, nobody (including your future self on another laptop) can see your work.

Git and GitHub

The idea

One-time setup

The everyday loop

Branches in one paragraph

.gitignore: what must never be committed

Good commit messages

Try it