" Maximun callbacks/second for tk and asyncio loops"

from tkinter import Tk
import time

root = Tk()
root.withdraw()
timer = time.perf_counter
seconds = 5
n = 0

def tktick():
    global n
    n += 1
    root.after(0, tktick)

def tkstop(tktickid):
    root.after_cancel(tktickid)
    delta = timer() - start
    print(delta, n, n//delta)
    root.quit()

root.after(1000 * seconds, tkstop, root.after(0, tktick))
start = timer()
root.mainloop()

##root.destroy()
##root = Tk()
##root.withdraw()
import asyncio
loop = asyncio.get_event_loop()

n = 0
def astick():
    global n
    n += 1
##    root.update()
    loop.call_soon(astick)

def asstop(astickid):
    astickid.cancel()
    delta = timer() - start
    print(delta, n, n//delta)
    loop.stop()

loop.call_later(seconds, asstop, loop.call_soon(astick))
start = timer()
loop.run_forever()