code: def translate_file(self, root, file_name, target_language):
          
          logger.info('filling up translations for locale `{}`'.format(target_language))
  
          po = polib.pofile(os.path.join(root, file_name))
          strings = self.get_strings_to_translate(po)
  
          # translate the strings,
          # all the translated strings are returned
          # in the same order on the same index
          # viz. [a, b] -> [trans_a, trans_b]
          tl = get_translator()
          translated_strings = tl.translate_strings(strings, target_language, 'en', False)
          self.update_translations(po, translated_strings)
          po.save()
docs: convenience method for translating a pot file
  
          :param root:            the absolute path of folder where the file is present
          :param file_name:       name of the file to be translated (it should be a pot file)
          :param target_language: language in which the file needs to be translated