tk additional window with Panda

I have a point in my program where a Tk window appears and then can be closed. I see the way Tk/Panda works an additional window is created. So when the actual window is closed, it is still there. How should one force it to close with the real one? Also, might there be a way to maybe have the actual window inside it so the issue will be less noticeable?

(I dont want to use Wx and add another dependency.)