title: Python 3 Tkinter - Messagebox with a toplevel as master?
body: <p>I've found that when a toplevel widget calls a messagebox dialog (like "showinfo"), the root window is showed up, over the toplevel. Is there a way to set the Toplevel window as the master of the messagebox dialog ?</p>
  
  <p>Here is a script to reproduce this :</p>
  
  <pre><code># -*- coding:utf-8 -*-
  # PYTHON 3 ONLY
  
  from tkinter import *
  from tkinter import messagebox
  
  root = Tk()
  root.title('ROOT WINDOW')
  Label(root, text = 'Place the toplevel window over the root window\nThen, push the button and you will see that the root window is again over the toplevel').grid()
  
  topWindow = Toplevel(root)
  topWindow.title('TOPLEVEL WINDOW')
  Label(topWindow, text = 'This button will open a messagebox but will\ndo a "focus_force()" thing on the root window').grid()
  Button(topWindow, text = '[Push me !]', command = lambda: messagebox.showinfo('foo', 'bar!')).grid()
  
  # --
  
  root.mainloop()
  </code></pre>