Does anybody know how to change that "Tk" in the upper left corner? I find it garish, and a distraction from the content. Using matplotlib for Python 2.5 on XP

Does anybody know how to change that "Tk" in the upper left corner? I find it garish, and a distraction from the content. Using matplotlib for Python 2.5 on XP. I don't think there's any way to get the window handle to send it a WM_SETICON and besides, it would be best to use a native Tk call.