How to use Google Cloud Translation API to translate XLIFF file in Python (example)

google-gloud-translate-xliff.py

#!/usr/bin/env python3

# USING
#
#   This script is an example; for more information, inspect the classes
# translate.storage.xliff.xlifffilename and
# translate.storage.xliff.xliffunit from the lib Translate Toolkit:
#
# https://docs.translatehouse.org/_/downloads/translate-toolkit/en/stable-1.12.0/pdf/
#
#   Also, the Google Cloud API documentation:
#
# https://cloud.google.com/translate/docs/reference/libraries/v2/python
#
# 1.   Change the three globals below accordingly (in uppercase)
#
# 2.   Install dependencies:
# pip install google-cloud-translate translate-toolkit\[all\]
# 
# 3.   Setup your Google Cloud Credentials in the
# envvar `GOOGLE_APPLICATION_CREDENTIALS`, for the project with
# the Translate API enabled, as in the docs:
#
# https://cloud.google.com/docs/authentication/getting-started
#
# 4.   Make the file executable and run it. The output filename will
# contain the current date as the script is executed.

import datetime

from translate.storage.xliff import xlifffile
from google.cloud import translate_v2

now = datetime.datetime.now()  # used to create the output file without
                               # overwriting anything
dumpfilename = now.strftime("%Y%m%d_%H%M%S-translation.txt")

XLIFF_FILENAME = "flarum-core-en.xlf"
SOURCE_LANGUAGE = "en"
TARGET_LANGUAGE = "pt"

a = open(XLIFF_FILENAME, 'r')

translate_client = translate_v2.Client()  # have you creds ready here

b = a.read()  # str()
c = b.encode('utf-8')  # bytes()

d = xlifffile(inputfile=c, sourcelanguage=SOURCE_LANGUAGE,
              targetlanguage=TARGET_LANGUAGE)

# d.getunits() -> list[xliffunit]
# e = d.getunits()[0]  # first xliffunit, as `unit` in the `for` below

totalunits = len(d.getunits())

for number, unit in enumerate(d.getunits()):
   res = translate_client.translate(unit.gettarget(),
                                    target_language=TARGET_LANGUAGE,
                                    format_="text")

   howmuch = "({}/{})".format(number, totalunits)
   source = res['input']
   translation = res['translatedText']
   print(howmuch, source, translation, sep='\n', end="\n\n")

   unit.settarget(translation, lang=TARGET_LANGUAGE)

d.savefile(dumpfilename)