gtk_dirs_to_include = ['etc', 'lib\\gtk-3.0', 'lib\\girepository-1.0',
    'lib\\gio', 'lib\\gdk-pixbuf-2.0', 'share\\glib-2.0', 'share\\fonts',
    'share\\icons', 'share\\themes\\Default', 'share\\themes\\HighContrast']
Creating an installer for a python GTK3 application