Gtk.FileChooserWidget() calls the GObject constructor, but it seems GtkFileChooserWidget doesn't actually expose the action as a property (which is odd, most other widgets to). It works fine with that.
In principle, your style of invocation should be invalid and generate an exception. The lack of an exception is what's causing this confusion, I'll have a closer look there.
I don't understand this:
chooser = Gtk.FileChooser Widget( self,
Gtk. FileChooserActi on.SELECT_ FOLDER)
What is the "self" there? As far as I can see, you should call the proper constructor:
chooser = Gtk.FileChooser Widget. new(Gtk. FileChooserActi on.SELECT_ FOLDER)
Gtk.FileChooser Widget( ) calls the GObject constructor, but it seems GtkFileChooserW idget doesn't actually expose the action as a property (which is odd, most other widgets to). It works fine with that.
In principle, your style of invocation should be invalid and generate an exception. The lack of an exception is what's causing this confusion, I'll have a closer look there.