Collaboration

Hamish Gibbs

Collaboration

  • Most programming isn’t solo.
  • In companies / research, you are often working on a small part of a larger project.
  • To collaborate - you need to share code!

Version control

  • To collaborate, we need:
    • A place to store a shared version of our code.
    • A way to track changes to different parts of the code.
  • Solution:
    • A “repository” to store our code
    • A version control system to track changes to the code

Local vs. Remote code

  • A repository stores the code for a specific project.
  • There are two different types of repository:
    • Local:
      • Think: a file folder on your computer.
    • Remote:
      • Think: a GitHub repository

Local vs. Remote code

  • With version control, I want my local changes to be reflected in the remote repository.

Git Repos

Image credit: Swarthmore Computer Science

git and GitHub

  • git is an open source version control system.
    • Purpose: recording and reconciling changes to code.
  • GitHub is a place to store remote repositories.

Why use git?

  • The best example:
  • You can:
    • Look at the history of changes: here
    • Go back to an earlier version of the course materials: here

Why use git?

  • git lets you:
    • Save a version of your code online.
    • Delete / modify code without losing anything.
  • I recommend:
    • Build a portfolio by saving any programming you do for your courses in GitHub.
    • This can show off your programming experience for jobs / graduate school.

Google docs

  • git is kind of like Google Docs.
    • I make a change to a document.
    • You make changes to the same document.
    • Our changes are combined together.
  • Except: git is very manual.

Version control

  • With git you need to be explicit about:
    • Saving changes (called ‘committing’).
    • ‘pushing’ local changes to the remote repository.
    • ‘pulling’ changes from the remote repository.
    • ‘merging’ changes together.
  • Good question: Why does this have to be so explicit?

Aims: today

  • This is a high-level introduction to git but it is sufficient for today.
  • We want to:
    • Create a place where we can compare everyone’s solutions to the Challenge.
    • Let everyone contribute their local code to this remote repository.

Aims: today

  1. Clone the shared repository:

    git clone [repo-url].git

  2. Copy your code to the cloned repository.

Aims: today

  1. Create your own branch.

    git checkout -b [my-branch]

  2. Add & commit your changes.

    git add [myfile].py
git commit -m "Adding my file!"

Aims: today

  1. Push your code to the remote repository:

    git push

  2. Pull other changes from the remote repository:

    git push

Other useful commands

  • After git add but before git commit:

    • Inspect which files have been created / modified / deleted:

      git status

    • Inspect changes to the code since the last commit:

      git diff --cached

Diving deeper into git

  • There is more to git:
    • Branching: creating different versions of the same code base.
    • Merging: combining different branches back into the main branch.
  • And more to GitHub:
    • Issue / project tracking
    • Automated actions

Tip

  • Github’s Education Benefits give you access to a lot of free stuff!
    • GitHub Copilot
    • GitHub Copilot Chat
    • Free web hosting