In Gtk, how to make a window smaller when creating - widget

Question

I am trying to display both an image and a box with an Entry widget. I can do that, but the window is so large that the widget at the bottom is mostly out of view. I have tried several calls to set the window's size or unmaximize it, but they seem to have no effect. I determined that the problem only occurs when the image is large, but still wonder how to display a large image in a resizable window or, for that matter, to make any changes to the window's geometry from code. All the function call I tried seem to have no effect.
Here is my code:
import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk
from gi.repository import GdkPixbuf
from urllib.request import urlopen
class Display(object):
def __init__(self):
self.window = Gtk.Window()
self.window.connect('destroy', self.destroy)
self.window.set_border_width(10)
# a box underneath would be added every time you do
# vbox.pack_start(new_widget)
vbox = Gtk.VBox()
self.image = Gtk.Image()
response = urlopen('http://1.bp.blogspot.com/-e-rzcjuCpk8/T3H-mSry7PI/AAAAAAAAOrc/Z3XrqSQNrSA/s1600/rubberDuck.jpg').read()
pbuf = GdkPixbuf.PixbufLoader()
pbuf.write(response)
pbuf.close()
self.image.set_from_pixbuf(pbuf.get_pixbuf())
self.window.add(vbox)
vbox.pack_start(self.image, False, False, 0)
self.entry = Gtk.Entry()
vbox.pack_start(self.entry, True,True, 0)
self.image.show()
self.window.show_all()
def main(self):
Gtk.main()
def destroy(self, widget, data=None):
Gtk.main_quit()
a=Display()
a.main()

Answer 1

Most of the posted information seems to pertain to Gtk2 rather than Gtk3, but there is a solution: to use a pix buf loader and set the size:
from gi.repository import Gtk, Gdk, GdkPixbuf
#more stuff
path = config['DEFAULT']['datasets']+'working.png'
with open(path,'rb') as f:
pixels = f.read()
loader = GdkPixbuf.PixbufLoader()
loader.set_size(400,400)
loader.write(pixels)
pb = GdkPixbuf.Pixbuf.new_from_file(path)
self.main_image.set_from_pixbuf(loader.get_pixbuf())
loader.close()