tkinter - Quit function for python 2 -

i'm following tutorial in python 3 using python 2. in tutorial following code used:

button2 = ttk.button(self, text="disagree", command = quit) 

when run code error:

nameerror: global name 'quit' not defined 

is there equivalent function use in python 2? tried sys.exit() froze tkinter window rather closing out.

tkinter wants root.quit(). (root root tkinter object)