[git/ipynb/nbformat] filter / clear output of ipython notebooks on git commit

.gitattributes

*.ipynb filter=filter_notebook

config

# add this to .git/config

[filter "filter_notebook"]
    clean = "./filter_notebook"

filter_notebook

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
clears all cells of an ipython notebook
given via stdin
by H.Dickten 2014
"""
import sys

try:
    import nbformat
except ImportError:
    sys.exit(1)


NBVERSION = 4


def clear_outputs(notebook, clear_prompt_numbers=True):
    """
    clears the output of all cells in an ipython notebook

    Parameters:
    ===========
    clear_promt_numbers: bool, optional
        clears the prompt numbers of all cells
        (default: True)
    """
    for cell in notebook.cells:
        if cell.get('cell_type', None) == 'code':
            cell.outputs = []
            if clear_prompt_numbers is True:
                cell.execution_count = None
                cell.pop('prompt_number', None)

    return notebook

if __name__ == '__main__':
    if len(sys.argv) > 1:
        INFILE = sys.argv[1]
    else:
        INFILE = sys.stdin
    if len(sys.argv) > 2:
        OUTFILE = open(sys.argv[2], 'w')
    else:
        OUTFILE = sys.stdout
    NB = nbformat.read(fp=INFILE, as_version=NBVERSION)
    NB = clear_outputs(NB)
    NBS = nbformat.writes(NB, version=NBVERSION).encode('utf-8')
    OUTFILE.write(NBS)