Prerequisite - Python - Creating window, button in GTK+ 3
In GTK+ rather than specifying the position and size of each widget in the window, you can arrange your widgets in rows, columns, and/or tables. The size of your window is determined automatically, based on the sizes of the widgets it contains. And the sizes of the widgets are, in turn, determined by the amount of text they contain. Perfecting the layout can be completed by specifying padding distance and centering values of widgets.
GTK+ arranges widgets hierarchically, using containers. There are two types of containers single-child containers and multiple-child containers. The most commonly used are vertical or horizontal boxes
Python3 1==
Output :
On clicking this we get.

(Gtk.Box) and grids (Gtk.Grid).
Follow below steps:
- import GTK+ 3 module.
- Create main window.
- Create Box.
- Create Button.
Gtk.Box.pack_start() (left to right ) or Gtk.Box.pack_end() (right to left). In a vertical box, widgets are packed from top to bottom or vice versa.
Example : Creating a box with button.
import gi
# Since a system can have multiple versions
# of GTK + installed, we want to make
# sure that we are importing GTK + 3.
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk
class MyWindow(Gtk.Window):
def __init__(self):
Gtk.Window.__init__(self, title ="GfG")
# Create a horizontally orientated box container
# having spacing 6 pixels
self.box = Gtk.Box(spacing = 6)
self.add(self.box)
# Add a button to box container.
# Gtk.Box.pack_start() widgets are positioned from left to right
self.button1 = Gtk.Button(label ="Click Here")
self.button1.connect("clicked", self.on_button1_clicked)
self.box.pack_start(self.button1, True, True, 0)
def on_button1_clicked(self, widget):
print("Welcome to Geeks for Geeks.")
win = MyWindow()
win.connect("destroy", Gtk.main_quit)
win.show_all()
Gtk.main()
On clicking this we get.
