There seems to be a memory leak in tkinter on OSX (Windows and Linux don't seem to be affected). Explicitly calling Tk.update() sometimes permanently allocates a multiple of 4096 bytes. Allocation happens more frequently if update calls are in close succession.

import time
from tkinter import Tk
root = Tk()

while True:
    root.update()  # Huge memory leak

while True:
    root.update()  # No memory leaks
    time.sleep(1)

Issue occurs on python3.3 and above, did not test on older versions.