Tkinter method deiconify seems not working on ubuntu(12.04, unity)

What you are seeing is apparently the difference between Windows and non-Windows. It looks to me like the Windows behavior is a bug. At the very least, it's not expected behavior. What you are seeing on ubuntu is what I would expect to see.

For a GUI to do anything, the event loop must be running. Everything that happens is the response to an event. The drawing of a window on the screen is a response to an event. A button click is a response to an event. The visual effect of a button being pressed is a response to an event. And so on.

When you call iconify, that causes an event to be sent to the app saying "remove the window from the screen". The event loop sees the event, and redraws (or "un"draws) the window. The reverse happens when you call deiconify -- the system gets a redraw event, and tkinter redraws the window on the screen.

In your code, you never give the event loop a chance to respond to these events. You ask it to iconfiy, then you sleep, then you deiconify, all without giving the event loop a chance to respond. While the sleep command is running no events are processed. So, when you wake from sleep, the system hides the window, and then microseconds later it redraws it.

What is probably happening on windows is that the window manager is getting the iconfiy command and removing the window without tkinter's involvement. In other words, tkinter doesn't actually do anything to make it go away. On X11-based systems, however, this is all managed by the event loop.

If you want the window to go away, and a second later reappear, use the event loop to your advantage. Allow the event loop to update the screen, and arrange for the deiconify to happen at sometime in the future. For example:

def close_handler(self):    self.root.iconify()    self.after(1000, self.root.deiconify)

This should work on all platforms. It allows the event loop to respond to the iconify event, and then a second later the deiconify command will run.