pyautogui 같은이미지가 나타날 때까지 sleep

import pyautogui
import time

while True:
    find_img = pyautogui.locateOnScreen('my_region.PNG')
    if find_img==None:
        print(find_img)
        time.sleep(5)
    else:
        break

center = pyautogui.center(find_img)
print(center)