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

class SwitcherWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="Switch Demo")
        self.set_border_width(10)

        hbox = Gtk.Box(spacing=6)
        self.add(hbox)

        switch = Gtk.Switch()
        switch.connect("notify::active", self.on_switch_activated)
        switch.set_active(False)
        hbox.pack_start(switch, True, True, 0)

        switch = Gtk.Switch()
        switch.connect("notify::active", self.on_switch_activated)
        switch.set_active(True)
        hbox.pack_start(switch, True, True, 0)

    def on_switch_activated(self, switch, gparam):
        if switch.get_active():
            state = "on"
        else:
            state = "off"
        print("Switch was turned", state)

win = SwitcherWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()