from gi.repository import GLib, GObject

class ObjWithProps(GObject.Object):
    @GObject.Property(type=int)
    def prop_with_underscore(self):
        return 5

    @GObject.Property(type=int)
    def prop(self):
        return 4

    def send_notify(self):
        self.notify('prop')
        self.notify('prop_with_underscore')


def main():
    loop = GLib.MainLoop.new(None, 0)

    def notify_1_callback(obj, pspec):
        print("Notify called for 'prop'")
    def notify_2_callback(obj, pspec):
        print("Notify called for 'prop_with_underscore'")
        loop.quit()

    obj = ObjWithProps()

    print("prop value: {}".format(obj.prop))
    print("prop_with_underscores value: {}".format(obj.prop_with_underscore))

    obj.connect('notify::prop', notify_1_callback)
    obj.connect('notify::prop_with_underscore', notify_2_callback)
    obj.send_notify()

    loop.run()

main()