How am I supposed to set a Gtk Notebook page tab expandable?

Question

When I add a page to a Gtk.Notebook programatically, I can't find a way to set the tab to expand. The property is available in Glade, so I know it can be done. Here is a snippet using reorderable and detachable properties.

#!/usr/bin/env python

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

class GUI:
    def __init__(self):

        window = Gtk.Window()
        notebook = Gtk.Notebook()
        window.add(notebook)
        for i in range (4):
            label = Gtk.Label('label in page number ' + str(i))
            tab_label = Gtk.Label('page ' + str(i))
            notebook.append_page(label, tab_label)
            notebook.set_tab_detachable(label, True)
            notebook.set_tab_reorderable(label, True)
        window.show_all()
        window.connect('destroy', Gtk.main_quit)

app = GUI()
Gtk.main()

However,

notebook.set_tab_expandable(label, True)

fails with

AttributeError: 'Notebook' object has no attribute 'set_tab_expandable'

Answer 1

The solution is:

notebook.child_set_property(label, 'tab-expand', True)