IDLE 2.7.11/12 “NameError: global name 'Toplevel' is not defined”

Question

I ran APT-GET update on a Debian based OS on Oracle VB. While it was running I messed around with some python code in IDLE 2.7.12 (I opened it with a terminal). After it finishe

Answer 1

The problem is a bug in the updated version of IDLE. Add the following near the top of .../Lib/idlelib/IOBinding.py, for instance before import tkFileDialog.

from Tkinter import *

The NameError occured in a function that displays a warning with the following message:

Non-ASCII found, yet no encoding declared. Add a line like
-*- coding:  -*-
Choose OK to save this file as 
Edit your general options to silence this warning

where will be an encoding such as utf-8.

It occurs to me that the message might be more helpful for beginners if it pointed to the Python Language Reference, Section 2.1.4., Encoding declarations

This bug is 2.x specific because in Python3, utf-8 is the default used in the absence of an encoding declaration.