problem with while statement.

[BobSmoss]

Hello,
I am new to python and cant seem to find an answer to my question.Here is what i am trying to do.

I want to make a loop that for example lastst for 10 seconds. Within those 10 sec I want to find an image, if that image is not found within those 10 sec i want it to run the else statement.

Here is what i have now.
   

import pyautogui
import time

t_end = time.time() + 10
while time.time() < t_end:
    if pyautogui.locateCenterOnScreen('image.png') is not None:
        print("found")
    else:
        print("Not found within the time frame")