<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _translate_table(self, dest_dir, table_name, translations_writer):
 """ Converts translations to the new format for a single table. """

        in_filename = os.path.join(self.src_dir, '%s.txt' % table_name)
        if not os.path.exists(in_filename):
            raise Exception('No %s' % table_name)

        out_filename = os.path.join(dest_dir, '%s.txt' % table_name)
        with open(in_filename, 'rb') as in_file:
            reader = csv.DictReader(in_file)
            if not reader.fieldnames or not any_translatable_field(
                    reader.fieldnames):
                print('Copying %s with no translatable columns' % table_name)
                shutil.copy(in_filename, out_filename)
                return 0
            table_translator = TableTranslator(
                table_name, reader.fieldnames, self.old_translations,
                translations_writer)
            with open(out_filename, 'w+b') as out_file:
                writer = csv.DictWriter(out_file, fieldnames=reader.fieldnames)
                writer.writeheader()
                for row in reader:
                    writer.writerow(table_translator.translate_row(row))

            table_translator.write_for_field_values()
            print('\ttranslation rows: %s' %
                  table_translator.total_translation_rows)
            return table_translator.total_translation_rows