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NOTE: using bash/git commands is not fully supported on jupyterlite yet (due to single thread/process restriction), and the cells below might error out on the browser (jupyterlite) version of this notebook
Before you can git pull, you need to have committed any changes you have made. If you find you want to pull, but you're not ready to commit, you have to temporarily "put aside" your uncommitted changes.
For this, you can use the git stash command, like in the following example:
import os
top_dir = os.getcwd()
git_dir = os.path.join(top_dir, 'learning_git')
working_dir = os.path.join(git_dir, 'git_example')
os.chdir(working_dir)
%%writefile Wales.md
Mountains In Wales
==================
* Pen y Fan
* Tryfan
* Snowdon
* Glyder Fawr
* Fan y Big
* Cadair Idris
%%bash
git stash
git pull
By stashing your work first, your repository becomes clean, allowing you to pull. To restore your changes, use git stash apply.
%%bash --no-raise-error
git stash apply
The "Stash" is a way of temporarily saving your working area, and can help out in a pinch.
Tagging¶
Tags are easy to read labels for revisions, and can be used anywhere we would name a commit.
Produce real results only with tagged revisions
%%bash
git tag -a v1.0 -m "Release 1.0"
git push origin --delete v1.0 # clear the tag if it already exists on the remote origin
git push --tags
%%writefile Pennines.md
Mountains In the Pennines
========================
* Cross Fell
* Ingleborough
%%bash
git add Pennines.md
git commit -m "Add Pennines"
You can also use tag names in the place of commmit hashes, such as to list the history between particular commits:
%%bash
git log v1.0.. --graph --oneline
If .. is used without a following commit name, HEAD is assumed.
Working with generated files: gitignore¶
We often end up with files that are generated by our program. It is bad practice to keep these in Git; just keep the sources.
Examples include .o and .x files for compiled languages, .pyc files in Python.
In our example, we might want to make our .md files into a PDF with pandoc:
%%writefile Makefile
MDS=$(wildcard *.md)
PDFS=$(MDS:.md=.pdf)
default: $(PDFS)
%.pdf: %.md
pandoc $< -o $@
%%bash
make
We now have a bunch of output .pdf files corresponding to each Markdown file.
But we don't want those to show up in git:
%%bash
git status
Use .gitignore files to tell Git not to pay attention to files with certain paths:
%%writefile .gitignore
*.pdf
%%bash
git status
%%bash
git add Makefile
git add .gitignore
git commit -m "Add a makefile and ignore generated files"
git push
Git clean¶
Sometimes you end up creating various files that you do not want to include in version control. An easy way of deleting them (if that is what you want) is the git clean command, which will remove the files that git is not tracking.
%%bash
git clean -fX
%%bash
ls
- with -f: don't prompt
- with -d: remove directories
- with -x: Also remote .gitignored files
- with -X: Only remove .gitignore files
Git Hunks¶
A "Hunk" is one git change. This changeset has three hunks:
+import matplotlib
+import numpy as np
from matplotlib import pylab
from matplotlib.backends.backend_pdf import PdfPages
+def increment_or_add(key,hash,weight=1):
+ if key not in hash:
+ hash[key]=0
+ hash[key]+=weight
+
data_path=os.path.join(os.path.dirname(
os.path.abspath(__file__)),
-regenerate=False
+regenerate=True
Interactive add¶
git add and git reset can be used to stage/unstage a whole file,
but you can use interactive mode to stage by hunk, choosing
yes or no for each hunk.
git add -p myfile.py
+import matplotlib
+import numpy as np
#Stage this hunk [y,n,a,d,/,j,J,g,e,?]?
GitHub pages¶
Yaml Frontmatter¶
GitHub will publish repositories containing markdown as web pages, automatically.
You'll need to add this content:
--- ---
A pair of lines with three dashes, to the top of each markdown file. This is how GitHub knows which markdown files to make into web pages. Here's why for the curious.
%%writefile index.md
---
title: Github Pages Example
---
Mountains and Lakes in the UK
===================
Engerland is not very mountainous.
But has some tall hills, and maybe a mountain or two depending on your definition.
%%bash
git add index.md
git commit -m "Add github pages YAML frontmatter"
The gh-pages branch¶
GitHub creates github pages when you use a special named branch.
This is best used to create documentation for a program you write, but you can use it for anything.
os.chdir(working_dir)
%%bash
git switch -c gh-pages
git push -uf origin gh-pages
The first time you do this, GitHub takes a few minutes to generate your pages.
The website will appear at http://username.github.io/repositoryname, for example:
UCL layout for GitHub pages¶
You can use GitHub pages to make HTML layouts, here's an example of how to do it, and how it looks. We won't go into the detail of this now, but after the class, you might want to try this.