Convert JSON data to URL encoded form (application/x-www-form-urlencoded)

JSON_to_URL_encoded_form.py

#!/usr/bin/env python3

import json
from urllib.parse import quote, quote_plus
import sys
import os
import argparse


parser = argparse.ArgumentParser(
    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    description='''
    JSON to URL-encoded form converter.
    If neither --object nor --file is given,
    the JSON object is read from standard input.''')
input_parser = parser.add_mutually_exclusive_group()
input_parser.add_argument(
    '--object', '-o', dest='obj',
    help='JSON object to parse.')
input_parser.add_argument(
    '--file', '-f', dest='file',
    help='JSON file to parse.')
parser.add_argument(
    '--no-plus', dest='quoter',
    action='store_const', const=quote, default=quote_plus,
    help='Encode a space with %%20 instead of +.')
parser.add_argument(
    '--safe', '-s', dest='safe',
    help='Safe characters to skip encoding.')
args = parser.parse_args()


if args.file is not None:
    with open(args.file, 'r') as f:
        data_s = f.read()
elif args.obj is not None:
    data_s = args.obj
else:
    # read JSON data from stdin
    data_s = ''
    while True:
        line = sys.stdin.readline()
        if not line.strip(' \r\n'):
            break
        data_s += line

if not data_s:
    sys.exit(0)

data_dec = json.loads(data_s)


def JSON_to_URL_encode(value, key=None):
    def quot(v, **kargs):
        if v is None:
            return ''
        if args.safe is not None:
            safe = kargs.pop('safe', '') + args.safe
            kargs['safe'] = safe
        return args.quoter('{!s}'.format(v), **kargs)

    def enc(k, v):
        return '{}={}'.format(quot(k, safe='[]'), quot(v))

    if isinstance(value, dict):
        iterator = value.items()
    elif isinstance(value, list):
        iterator = enumerate(value)
    elif key is None:
        # top level object was neither list nor dictionary
        raise TypeError('Only lists and dictionaries supported')
    else:
        return enc(key, value)

    res_l = []
    for k, v in iterator:
        if key is None:
            this_key = k
        else:
            this_key = '{}[{}]'.format(key, k)
        res_l.append(JSON_to_URL_encode(v, key=this_key))
    return '&'.join(res_l)


print(JSON_to_URL_encode(data_dec))