Simple python script to format a json string sending the output to stdout or another file

json_formatter.py

import json
import argparse
import sys

def format_json(input, output):
  try:
    with open(input, 'r') as ifile:
      contents = json.load(ifile)
  except IOError as e:
    print(e)
    sys.exit(1)

  if output != None:
    try:
      with open(output, 'w') as ofile:
        json.dump(contents, ofile, sort_keys=True, indent=2, separators=(',', ': '))
    except IOError as e:
      print(e)
      sys.exit(1)
  else:
    print (json.dumps(contents, sort_keys=True, indent=2, separators=(',', ': ')))

if __name__ == '__main__':
  parser = argparse.ArgumentParser(description='Format json file to make it easier to read for humans')
  parser.add_argument('input_file', type=str, nargs=1)
  parser.add_argument('output_file', type=str, nargs='?')
  args = parser.parse_args()
  ifile = args.input_file[0]
  ofile = args.output_file if args.output_file != None else None
  format_json(ifile, ofile)