from Tkinter import *
def dialog():
win = Toplevel()
Label(win, text='Info!').pack()
Button(win, text='OK', command=win.quit).pack()
win.protocol('WM_DELETE_WINDOW', win.quit)
win.focus_set()
win.grab_set()
win.mainloop()
win.destroy()
print 'dialog exit'
root = Tk()
Button(root, text='popup', command=dialog).pack()
root.mainloop()