json_prettifier.py

import argparse
import json


def prettify(filename, indent=2, output_filename=None):
    with open(filename) as fobj:
        data = json.load(fobj)
    with open(output_filename or filename, mode="w") as fobj:
        json.dump(data, fobj, indent=indent)


if __name__ == "__main__":
    parser = argparser.ArgumentParser()
    parser.add_argument("input_filename")
    parser.add_argument("--output-filename")
    parser.add_argument("--indent", default=2)
    args = parser.parse_args()

    prettify(filename, indent=args.indent, output_filename=args.output_filename)