changing gtkpixmap image

[yoioque]

hi,
i'm trying for a long time to use the gtk_pixmap_set to change the pixmap
of a gtkpixmap widget, but i allways got the same error, i don't
understand it :-//

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Traceback (most recent call last):
  File "/usr/lib/python2.2/site-packages/gtk.py", line 130, in __call__
    ret = apply(self.func, a)
  File "<stdin>", line 15, in flip
  File "/usr/lib/python2.2/site-packages/gtk.py", line 2342, in set
    _gtk.gtk_pixmap_set(self._o, pixmap, mask)
TypeError: gtk_pixmap_set() argument 3 must be GdkWindow, not None
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i didn't found any working example about it, so could
someone help me ?

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from gtk import *
import GdkImlib

window = GtkWindow()
window.connect('destroy', mainquit)
boutton = GtkButton('flip')
vbox = GtkVBox()
window.add(vbox)

def flip(self):
    image = GdkImlib.Image("00002.JPG")
    image.render()
    pixmap, mask = image.get_pixmap()
    logo.set(pixmap, mask)             # ERROR is here
    logo.show()
          
image = GdkImlib.Image("00001.JPG")
image.render()
pixmap, mask = image.get_pixmap()
logo = GtkPixmap(pixmap, mask)
logo.show()

boutton.connect('clicked', flip)
vbox.pack_start(logo)
vbox.pack_start(boutton)
window.show_all()

mainloop()
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