sequentially re-numbers cells in an IPython Notebook file

ipynb_renum.py

#!/usr/bin/python
#
# sequentially re-numbers cells in an IPython notebook
# 2014.12.26 darell tan
#

import json
import sys

def main():
	f1 = open(sys.argv[1], 'rb')
	f2 = open(sys.argv[1] + '.new', 'wb')

	cell_num = 1

	nb = json.load(f1)
	for cell in nb['worksheets'][0]['cells']:
		if 'prompt_number' in cell:
			cell['prompt_number'] = cell_num
			cell_num += 1

	json.dump(nb, f2, indent=1, separators=(',', ': '), sort_keys=True)
	f1.close()
	f2.close()

if __name__ == '__main__':
	main()