from gi.repository import Gtk class MyWindow(Gtk.Window): def __init__(self): Gtk.Window.__init__(self, title="Hello World") self.box = Gtk.Box(spacing=6) self.add(self.box) self.button1 = Gtk.Button(label="Hello") self.button1.connect("clicked", self.on_button1_clicked) self.box.pack_start(self.button1, True, True, 0) def on_button1_clicked(self, widget): print("Hello") def on_button2_clicked(self, widget): print("Goodbye") self.button2 = Gtk.Button(label="Goodbye") self.button2.connect("clicked", self.on_button2_clicked) self.box.pack_start(self.button2, True, True, 0) win = MyWindow() win.connect("delete-event", Gtk.main_quit) win.show_all() Gtk.main()