import pygtk
pygtk.require('2.0')
import gtk

import wnck

def main():
    screen = wnck.screen_get_default()
    # Process pending gtk+ events so that wnck can find out about existing windows.
    while gtk.events_pending():
        gtk.main_iteration()
    for window in screen.get_windows():
        for window in screen.get_windows():
            # A XID is a number that identifies a X window.
            xid = window.get_xid()
            # By calling gtk.gdk.window_foreign_new(xid), we are creating
            # a gtk.gdk.Window which wraps the window that is identified by
            # the XID. It will return None if it can't find the X window
            # identified by the XID in question.
            wrapped_window = gtk.gdk.window_foreign_new(xid)
            # We are maximizing the window here, but
            # you can do almost anything with a gtk.gdk.Window.
            wrapped_window.maximize()

if __name__ == '__main__':
    main()