i18njson translate using Google Translate

1-usage.txt

$ python i18njson-translate.py --help                                                      
Usage: i18njson-translate.py [OPTIONS] INPUTFILE OUTPUT

  Process and translate .po or JSON files and generate translated .po file
  in result. Can work with exist .po files and if in initial file msgid
  dissapear then mark translaed string as obsolete. Try to play nice with
  version control systems and follow initial file order format, you will get
  predicteable diffs.

Options:
  --lang TEXT        From what language text should be translated. Use one of
                     Google Translate languages codes. Example: 'en'
  --to TEXT          Target language should be in result file
  --paid             Use paid API with key
  --ftype [json|po]  Accept input file in json or po format
  --help             Show this message and exit.

i18njson-translate.py

import os
import click
import polib
from collections import OrderedDict
import commentjson as json
try:
    import urllib2 as request
    from urllib import quote
except:
    from urllib import request
    from urllib.parse import quote

AGENT = u"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:36.0) Gecko/20100101 Firefox/36.0"
URL = u"http://translate.google.com/translate_a/t?client=p&ie=UTF-8&oe=UTF-8" + \
    u"&sl={lang}&tl={to}&text={text}"
API_KEY = u""  # Insert API key here


def call_paid_api(message, lang, to):
    from googleapiclient.discovery import build
    service = build('translate', 'v2', developerKey=API_KEY)
    res = service.translations().list(source=lang, target=to, q=message).execute()
    return res['translations'][0]['translatedText']


def call_api(message, lang, to):
    quoted = quote(message, '')
    headers = {'User-Agent': AGENT}
    req = request.Request(
        url=URL.format(lang=lang, to=to, text=quoted),
        headers=headers)
    r = request.urlopen(req)
    result = r.read().decode('utf-8')

    return json.loads(result)['sentences'][0]['trans']


@click.command()
@click.argument('inputfile', type=click.Path())
@click.argument('output', type=click.Path())
@click.option('--lang', help="From what language text should be translated." + \
    " Use one of Google Translate languages codes. Example: 'en'")
@click.option('--to', help='Target language should be in result file')
@click.option('--paid', help='Use paid API with key',
    default=False, is_flag=True)
@click.option('--ftype', help='Accept input file in json or po format',
    type=click.Choice(['json', 'po']))
def process(inputfile, output, lang, to, paid, ftype):
    """ Process and translate .po or JSON files and generate translated .po
    file in result. Can work with exist .po files and if in initial file
    msgid dissapear then mark translaed string as obsolete. Try to play nice
    with version control systems and follow initial file order format,
    you will get predicteable diffs.

    """

    if ftype == 'json':
        items = json.load(open(inputfile), object_pairs_hook=OrderedDict)
    else:
        items = OrderedDict()
        ifile = polib.pofile(inputfile)
        for entry in ifile:
            items[entry.msgid] = entry.msgstr


    created = False
    if os.path.exists(output):
        po = polib.pofile(output)
    else:
        po = polib.POFile()
        created = True
        po.metadata = {
            'Project-Id-Version': '1.0',
            'Report-Msgid-Bugs-To': 'you@example.com',
            'POT-Creation-Date': '2007-10-18 14:00+0100',
            'PO-Revision-Date': '2007-10-18 14:00+0100',
            'Last-Translator': 'you <you@example.com>',
            'Language-Team': 'English <yourteam@example.com>',
            'MIME-Version': '1.0',
            'Content-Type': 'text/plain; charset=utf-8',
            'Content-Transfer-Encoding': '8bit',
        }

    for k, v in items.items():
        if paid:
            translated = call_paid_api(v, lang, to)
        else:
            translated = call_api(v, lang, to)
        entry = po.find(k, by="msgid", include_obsolete_entries=True)
        if entry:
            entry.msgstr = translated
            entry.obsolete = False  # mark not obsolete anymore
        else:
            entry = polib.POEntry(msgid=k, msgstr=translated)
            po.append(entry)

    for entry in po:
        if not entry.msgid in items:
            click.echo("msgid '{}' marked as obsolete".format(entry.msgid))
            entry.obsolete = True

    if created:
        po.save(fpath=output)
    else:
        po.save()


if __name__ == '__main__':
    process()

requirements.txt

click
polib
commentjson
google-api-python-client