Why doesn't tkinter play nicely with multiprocessing?

Question

The following code hangs without doing anything in python 3.2.2 in linux:

import tkinter
from multiprocessing import Process

def f():
    root = tkinter.Tk(         


        

Answer 1

As of September 2013, there are some additional comments on the bug report that give more insight into what the actual problem is.

http://bugs.python.org/issue5527#msg194848
http://bugs.python.org/issue5527#msg195480

Based on the above, I'm guessing something like the following is happening: Tkinter is not thread safe, so (for whatever reason) Tkinter wants to know which thread is the main thread. Tkinter assumes that the main thread when the Tkinter module is loaded will also be the main thread for program execution. When you fork or multiprocess after loading Tkinter, this assumption is broken. (For example, after a fork, the remembered main thread is in the parent, not the child.)