Why does the time.sleep command not work for me as it should?

Question

Python

Why, when executing this loop, falling asleep does not occur after update(), as it should, but after executing the next command after sleep?
The code below outputs:
Enter
Update
Enter
and only then goes to sleep.
Update
Input goes to
sleep
etc.

from time import sleep, time

FPS = 1
SEC_PER_FRAME = 1/FPS

def processInput():
    print("Ввод")

def update():
    print("Update")

while True:
    start = time()
    processInput()
    update()
    sleep(start + SEC_PER_FRAME - time())

Answer 1

add print (start + SEC_PER_FRAME - time())
everything at once it will be clear