I18n at GTK4 and Python

[Andreas]

Hi,
I’m writing a Python app with GTK4 for Linux (Ubuntu 24) and Windows. I’m still a beginner.

This is my menu:

<?xml version='1.0' encoding='UTF-8'?>
<interface>
  <requires lib="gio" version="2.0"/>
  <menu id="menubar">
    <submenu>
      <attribute name="label" translatable="yes">_File</attribute>
     <section>
        <item>
          <attribute name="action">app.new</attribute>
          <attribute name="label" translatable="yes" >_New</attribute>
         <attribute name="accel">&lt;Ctrl&gt;n</attribute>
        </item>
        <item>
        <attribute name="label" translatable="yes">_Quit</attribute>
        <attribute name="action">app.quit</attribute>
        <attribute name="accel">&lt;Primary&gt;q</attribute> 
      </item>
      </section>
    </submenu>
  </menu>
</interface>

In Linux, my menu items will be translated, but not the keyboard labels:

os.environ["LANG"] = "de_DE.utf8"
os.environ["LANGUAGE"] = "de_DE.utf8"
locale.setlocale(locale.LC_ALL, 'de_DE.utf8')
locale.bindtextdomain("test-menu", "locale")
locale.textdomain("test-menu")

In English, I see “New Ctrl+N” and “Quit Ctrl+Q”. In German, I see “Neu Ctrl+N” and “Beenden Ctrl+Q”. How can I ensure that when I select German there is a Strg+N or Strg+Q and no Ctrl+N or Ctrl+Q?

In Windows, the locale approach does not work. Simple gettext in Python has no link to GTK. I used the latest release from https://github.com/wingtk/gvsbuild?tab=readme-ov-file.
So, I tried this, also with de and de_DE and the menu items “File”, “New” and “Quit” weren’t translated. But, I see Strg+N and Strg+Q:

os.environ["LANGUAGE"] = "de_DE.utf8"
os.environ["LANG"] = "de_DE.utf8"
locale.setlocale(locale.LC_ALL, 'de_DE.utf8')
libintl = ctypes.cdll.LoadLibrary(r"c:\gtk\bin\intl.dll")
libintl.bindtextdomain("test-menu", "locale")
libintl.textdomain("test-menu")

How can I make these menu items localize in Windows?

With plain text, I use po and mo files. If I also want to use different hotkeys for different user languages what kind of approach would you recommend? Maybe different ui files?

Kind regards,
Andreas