time.sleep( ) does not work for anaglyph( ) in python

time.sleep( ) does not work for anaglyph( ) in python

Is the time.sleep function in python useful only for codes like
"print(...)" but not for "anaglyph(...)?"?
What I want is : first anaglyph the pic for x seconds. then clean the screen.
When I add" time.sleep(x)" in my code and run the whole, my out put is
totally empty -- it directly goes to the next line clear_all(). But when I
use time.sleep(x) with print("You are the apple of my eyes"), it works
well.
Can I know what have happened?
How can I get what I want ?
Looking for solutions :)))
Would appreciate a lot :)
thank you :)