operator.itemgetter or lambda

I was curious if there was any indication of which of operator.itemgetter(0) or lambda x:x[0] is better to use, specifically in sorted() as the key keyword argument as that’s the use that springs to mind first. Are there any known performance differences? Are there any PEP related preferences or guidance on the matter?

Trying to delay a specific function for spawning enemy after a certain amount of time

I am making a mole shooter game using pygame. I want my mole to spawn at a random position after every 1 second. I have tried using time.sleep(1.0) but that delays my whole code and thus the game doesn’t function properly because of delayed responses. I am moving an aim using the mouse(which also gets affected because of time.sleep) to which i will be adding a click to shoot. I need help with delaying and spawning my mole. I would also like some opinions on how to organize my code to provide various levels of difficulty and a main menu later on.