gettext

(You can also check this code in the repository)

from pathlib import Path
import gettext
import sys

from PySide6.QtCore import QItemSelection, QLocale, Qt, Slot
from PySide6.QtWidgets import (QAbstractItemView, QApplication, QListWidget,
                               QMainWindow, QWidget)


_ = None
ngettext = None


class Window(QMainWindow):
    def __init__(self):
        super().__init__()
        file_menu = self.menuBar().addMenu(_("&File"))
        quit_action = file_menu.addAction(_("Quit"))
        quit_action.setShortcut(_("CTRL+Q"))
        quit_action.triggered.connect(self.close)

        self._list_widget = QListWidget()
        self._list_widget.setSelectionMode(QAbstractItemView.MultiSelection)
        self._list_widget.selectionModel().selectionChanged.connect(self.selection_changed)
        self._list_widget.addItem("C++")
        self._list_widget.addItem("Java")
        self._list_widget.addItem("Python")
        self.setCentralWidget(self._list_widget)

    @Slot(QItemSelection, QItemSelection)
    def selection_changed(self, selected, deselected):
        count = len(self._list_widget.selectionModel().selectedRows())
        message = ngettext("{0} language selected",
                           "{0} languages selected", count).format(count)
        self.statusBar().showMessage(message)


if __name__ == '__main__':
    app = QApplication(sys.argv)

    src_dir = Path(__file__).resolve().parent
    try:
        translation = gettext.translation('example', localedir=src_dir / 'locales')
        if translation:
            translation.install()
            _ = translation.gettext
            ngettext = translation.ngettext
    except FileNotFoundError:
        pass
    if not _:
        _ = gettext.gettext
        ngettext = gettext.ngettext
        print('No translation found')

    window = Window()
    window.show()
    sys.exit(app.exec())
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PySide6 gettext example\n"
"POT-Creation-Date: 2021-07-05 14:16+0200\n"
"Language: de_DE\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Plural-Forms: nplurals=2; plural==n != 1;\n"

#: main.py:57
msgid "&File"
msgstr ""

#: main.py:58
msgid "Quit"
msgstr ""

#: main.py:59
msgid "CTRL+Q"
msgstr ""

#: main.py:73
#, python-brace-format
msgid "{0} language selected"
msgid_plural "{0} languages selected"
msgstr[0] ""
msgstr[1] ""
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PySide6 gettext example\n"
"POT-Creation-Date: 2021-07-05 14:16+0200\n"
"Language: de_DE\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Plural-Forms: nplurals=2; plural=n != 1;\n"

#: main.py:57
msgid "&File"
msgstr "&Datei"

#: main.py:58
msgid "Quit"
msgstr "Beenden"

#: main.py:59
msgid "CTRL+Q"
msgstr "CTRL+B"

#: main.py:73
#, python-brace-format
msgid "{0} language selected"
msgid_plural "{0} languages selected"
msgstr[0] "{0} Sprache ausgewählt"
msgstr[1] "{0} Sprachen ausgewählt"