#!/usr/bin/python

import argparse
import json
from operator import itemgetter

parser = argparse.ArgumentParser()
parser.add_argument("paths", nargs="+", help="path to the json file")
parser.add_argument("--sort-by", help="dictionary key to sort by")
args = parser.parse_args()

for path in args.paths:
    in_file = open(path, "rb")
    data = json.load(in_file)
    in_file.close()

    if args.sort_by is not None:
        data.sort(key=itemgetter(args.sort_by))         

    out_file = open(path, "wb")
    json.dump(data, out_file, sort_keys=True, indent=4)
    out_file.write('\n')
    out_file.close()