Strip output of Jupyter notebooks on git add

.git_config

[filter "strip_ipynb"]
    clean = python3 strip_ipynb.py

.gitattributes

*.ipynb filter=strip_ipynb

strip_ipynb.py

#! /usr/bin/env python
# this script filters output from ipython notebooks, for use in git repos
# http://stackoverflow.com/questions/18734739/using-ipython-notebooks-under-version-control
#
# put this file in a `bin` directory in your home directory, then run the following commands:
#
# chmod a+x ~/bin/ipynb_output_filter.py
# echo -e "*.ipynb \t filter=dropoutput_ipynb" >> ~/.gitattributes
# git config --global core.attributesfile ~/.gitattributes
# git config --global filter.dropoutput_ipynb.clean ~/bin/ipynb_output_filter.py
# git config --global filter.dropoutput_ipynb.smudge cat

# works with Notebook versions 3, 4 and 5 (iPython/Jupyter versions 2, 3 and 4)
import sys
from nbformat import read, write, NO_CONVERT

json_in = read(sys.stdin, NO_CONVERT)

# detect earlier versions
if ('worksheets' in json_in):
    # versions prior to 4 had a 'worksheets' field with a single element
    sheet = json_in.worksheets[0]
else:
    sheet = json_in

for cell in sheet.cells:
    if "outputs" in cell:
        cell.outputs = []
    if "prompt_number" in cell:
        cell.prompt_number = None
    if "execution_count" in cell:
        cell.execution_count = None

write(json_in, sys.stdout, NO_CONVERT)

This automatically strips Jupyter NoteBooks output cells when adding files to a git repository.
This is useful to reduce garbage checked into the repo.

Copy the Python script and the .gitattributes files to the repo, and set the config. Make the script executable.

Might also be done with git config filter.strip_ipynb.clean "python3 strip_ipynb.py" .

Based on the following:
https://gist.github.com/minrk/6176788
https://gist.github.com/waylonflinn/010f0a1a66760adf914f
https://github.com/cfriedline/ipynb_template/blob/master/nbstripout
https://github.com/kynan/nbstripout