Lecture Lab 7

Which questions you can answer after today’s lecture?

• What does version control mean?

  • How does Git and GitHub relate to this and what is their difference?

• Why do Git and teamwork go hand in hand in data science?

• How to use Git in a team

Git/GitHub - Why you should care

• Teamwork and Git belong together in Data Science/Computer Science

• GitHub and reproducible data science go hand in hand

• There will be the moment when git will safe a lot of time in a big project

Things that happen without version control

Version Control - What and why

Think about your own a experiences with coding and how a system could remove these issues. Also what should this system have if you work with others on one project

Collect your ideas at the course Padlet

Version Control - Definition

• Version control is like a special “undo” button for your work.

• remembers all the changes you make, so you can always go back to an older version

• Lets you and your friends work on the same project without mixing up each other’s changes.

Git - An open source version control system

• installed locally on your device

• keeps track of your file changes

  • each change is indexed, so you can revert your current state

• You interact with it via the terminal and control your local repository

GitHub

• Hub = Server where you can find, store and manage repositories

  • everything is remote

• a platform which provides a GUI for your repository and enables users to share code easily

• you interact with it via an application or a web browser and control your remote repository

Git and GitHub together

• GitHub allows you to have the project repository remotely

• Multiple people who have git installed can then access this repository and create a copy

• GitHub introduces visual features and eases the project management

Git - The basics

staging area = like a container with the changes for the next commit

Git - simple workflow when working together

If you forget to pull…

• if you and your teammate work on the same codeline and both push the results to the remote repository, git will detect a merge conflict

• conflict = two changes in the same line of the same file

  ! git will not know the version you prefer

Git in RStudio

Git in RStudio - Commit in GUI

• commit message = very short summary of new changes to your project

GitHub - Overview

• you can browse through all open source software

GitHub - Use the README!

• README.md is like a quarto document
  • you can combine code and text to design a short “manual” for your users

Git - working together with clone or fork

• you can create a copy of the current state of the project by cloning or forking

  • cloning: work in same remote repository

  • forking: create and work in your own remote repository

Git - When should I use clone and fork now?

• it is a question of:

  • How much control do I want?

  • How do I want to continue with the project as a collaborator?

• fork = you will have complete control over the repository

  • BUT your collaborators will not be able to apply and use your changes

• If you plan to contribute to a target repository you typically clone it

Git - Branches

• branch: new separate and isolated version of the mother branch

  • useful for: experimenting, bug fixing, adding features

  • see it as a structural component for organizing a project

Git - Merge

• helps to combine changes from two branches into a single branch

• current branch: The branch to be merged

• target branch: The branch in which we want to merge the current branch

• Why F in merged target branch?

  = new index for a new commit

Questions? …