Small python gtk sample.

gtk2.py

from gi.repository import Gtk, GLib


class LedControl(Gtk.Window):
    """
        A simple app that changes images according to the button status.
    """
    def __init__(self):
        Gtk.Window.__init__(self, title="LED Control")
        self.set_border_width(6)
        self.set_default_size(200, 250)
        self.blink_counter = 0
        GLib.timeout_add(500, self.blink_timer, None)

        okno = Gtk.Table(5, 2, True)
        self.add(okno)

        self.leds = []
        for i in range(4):
            button = Gtk.ToggleButton("LED %s" % i)
            button.connect("toggled", self.led_button_handler, str(i))
            button.set_border_width(2)
            img = Gtk.Image()
            img.set_from_file("LED_off.png")
            okno.attach(button, 0, 1, i, i + 1)
            okno.attach(img, 1, 2, i, i + 1)
            self.leds.append(img)

        self.blinking_on = Gtk.ToggleButton("Blikanie")
        self.blinking_on.set_border_width(2)
        okno.attach(self.blinking_on, 0, 1, 4, 5)

    def led_button_handler(self, button, name):
        """
            When a led-related button was pressed.
        """
        self.leds[int(name)].set_from_file(
            "LED_on.png" if button.get_active() else "LED_off.png",
        )

    def blink_timer(self, dummy_data):
        """
            Timer to control blinking.
        """
        self.blink_counter += 1
        if self.blinking_on.get_active():
            print "Blinking [%s]" % self.blink_counter
            for led in range(4):
                self.leds[led].set_from_file(
                    "LED_on.png" if self.blink_counter % 2 else "LED_off.png",
                )
        else:
            print "Not blinking [%s]" % self.blink_counter
        return True

if "__main__" == __name__:
    app = LedControl()
    app.connect("delete-event", Gtk.main_quit)
    app.show_all()
    Gtk.main()