Threaded Tkinter script crashes when creating the second Toplevel widget

Question

I have a Python script which uses Tkinter for the GUI. My little script should create a Toplevel widget every X seconds. When I run my code, the first Toplevel widget is cre

Answer 1

Is there a reason you want (or think you need) one event loop per toplevel window? A single event loop is able to handle dozens (if not hundreds or thousands) of toplevel windows. And, as has been pointed out in another answer, you can't run this event loop in a separate thread.

So, to fix your code you need to only use a single event loop, and have that run in the main thread.