Using the gtk from Python.

python_gtk.py

import gtk

class GtkTutorial:

    def __init__(self):
        #GTK Window
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.set_border_width(1)
        self.window.set_title('Tutorial')
        self.window.set_default_size(1024, 768)
        self.window.connect('delete_event', self.destroy)

        #GTK MessageDialog
        self.message = gtk.MessageDialog(type=gtk.MESSAGE_ERROR, buttons=gtk.BUTTONS_OK)
        self.message.set_markup('ok!')

        #GTK Button
        self.button = gtk.Button('Hello World')
        self.button.connect('clicked', self.showMessage, None)

        #GTK Drawing Area
        self.drawingArea = gtk.DrawingArea()
        self.drawingArea.set_size_request(10, 10)

        self.window.add(self.drawingArea)
        self.window.add(self.button)

        self.button.show()
        self.window.show()

    def main(self):
        gtk.main()

    def destroy(self, widget, data=None):
        gtk.main_quit()

    def showMessage(self, widget, event, data=None):
        self.message.run()

tutorial = GtkTutorial()
tutorial.main()