test.py

import pyglet
from time import time

window = pyglet.window.Window()
last_update = time()
def update(*args):
	global last_update
	print('Update was called every:', time()-last_update,'seconds')
	last_update = time()

@window.event
def on_draw():
	dt = pyglet.clock.tick()
	print('Last time tick() was called:', dt,'seconds ago')

pyglet.clock.schedule_interval(update, 1.0 / 60.0)
pyglet.app.run()