Git & GitHub Overview

Data Visualization Institute for Librarians

Heidi Tebbe | Bret Davidson

Slides

bretdavidson.github.io/dvil_github

The Plan

• Why use version control systems?
• What is Git?
• What is GitHub?
• Evaluating software projects on GitHub.
• Using GitHub without the command line.
• Non-code uses for Git & GitHub.

Why use version control?

How to save documents!

• annual.docx
• annual_final.docx
• annual_final_JC.docx
• annual_final_JC_2.docx
• annual_final_final.docx
• annual_final_final_corrected.docx
• FINAL_annual_final.docx

What does version control do?

• Records the history of changes to a set of related files inside of a "repository".
• Enables navigation of that change history.
• Supports sharing of the repository among a group of collaborators.

Two Kinds of Version Control

• Centralized
  • Examples are CVS and Subversion
• Distributed
  • Examples are Git and Mercurial

What is Git?

• Git is a distributed version control system.
• Original author is Linus Torvalds, of Linux fame.
• "I'm egotistical, and I name all my projects after myself."
• git means "unpleasant person" in British slang.

What is GitHub?

• GitHub is a Git repository hosting service.
• Adds services on top of Git like issues, wikis, and social networking.

Common Commands

checkout/clone

obtain a copy of a repository

pull/sync

update your local copy of repo to the latest version

branch

create a separate version of the files in the repo

commit

record a set of changes

push/publish

send your changes to the central or remote repo

Critical Features of GitHub

• Fork
• Pull Request

fork

create a copy (clone) in order to make your own changes

use someone else's project as a starting point OR propose changes to the original

pull request

mechanism for submitting your changes to original project

project owner "pulls" in your changes

Web Client Overview

github.com/bretdavidson

github.com/cazzerson/Suma

What is GitHub Desktop?

desktop.github.com

Non-code Uses

• Knowledge Base
• Data Management
• Communication

Knowledge Base

https://github.com/NCSU-Libraries/visualization_templates

Visualization Templates

Diffing Images

Caveats

• No ZIP files for folders
• Not a digital asset management system
• Licenses

Data Management

Making Your Code Citable

Communication

• Jupyter Notebooks
• GitHub Pages

Jupyter Notebooks

• interactive environments that can contain executable code, rich text, mathematics, plots
• support over 40 programming languages, including Python and R
• Jupyter Notebook App : server-client application that allows editing and running of notebook documents via a web browser
• Jupyter Notebook Viewer : free web service that allows you to share static versions of publicly available hosted notebook files
• render directly on GitHub

Pages

https://pages.github.com

http://cazzerson.github.io/Suma

Logistics

File and Repository Sizes

• git : no file size or file number limits
• GitHub repositories : 1 GB
• files added to GitHub via browser : 25 MB limit
• files added to GitHub via command line : 100 MB limit
• files stored using Git Large File Storage (LFS) : 2 GB limit

Public vs. Private

• git : private
• free GitHub account : public
• paid GitHub plans : public AND private
• students using GitHub : public AND private

Further Learning

Free Tutorials

• Try Git: https://www.codeschool.com/courses/try-git
• Pro Git Ebook: https://git-scm.com/book/en/v2
• GitHub Guides: https://guides.github.com

Documentation

• git Documentation: https://git-scm.com/documentation
• GitHub Help: https://help.github.com

Questions?