On Thu, 25 Feb 2021 11:06:05 -0500 Richard Damon <rich...@damon-family.org> wrote:
> On 2/24/21 6:35 AM, John O'Hagan wrote: > > Here is some minimal, non-threaded code that reproduces the problem > > on my system (Xfce4 on Debian testing): > > > > from tkinter import * > > from random import randint > > > > root = Tk() > > > > def display(label): > > label.destroy() > > label = Label(text=randint(0, 9)) > > label.pack() > > root.after(100, display, label) > > > > display(Label()) > > mainloop() > > > > This opens a tiny window that displays a random digit on a new label > > every .1 second. (Obviously I could do this by updating the text > > rather than recreating the label, but my real application has to > > destroy widgets and create new ones). > > > > This works for 3-4 hours, but eventually the window freezes. > > > > The process uses about 26 Mb of memory at first, and this gradually > > increases to around 30 or so by the time it freezes. > > > > Any ideas what could be causing this, or even how to approach > > debugging or workarounds? > > > > Thanks > > > > -- > > > > John > > One thought is that repeatedly destroying and recreating a label might > be leaking a resource. One option would be to change the code to just > update the label rather than recreating it each time. Simplest is > probably to link the Label to a StringVar instead of a fixed text and > updating the variable to change the text. You can also (I believe) go > into the Label and change the text it has with a configuration call. > Thanks for your reply. It's true that your suggested approach stops the leak (if that's what it is!) in the example code, but IMO there are valid use-cases where it's necessary (or at least desirable) to continually create new widgets and then destroy them in the course of running the application. In my use-case, the application reads YOLO object-recognition data from video, and displays data about each new object in a new frame. When the object ceases to be visible, the frame is destroyed. I suppose I could redesign, e.g. by withdrawing frames instead of destroying them, and keeping them in a pool to re-use later for new data streams as needed. I'll give that a try if I can't solve this issue. Thanks -- John -- https://mail.python.org/mailman/listinfo/python-list
