[cr33pyguy]

"elif" means else-if. I'm pretty sure it can function without an "else" but will shutdown if there is neither "yes" nor "no" in the input.

yes, I was aware of the meaning of elif.
I just remember reading in the docs somewhere that all if statements need an "else" part. That could've been Java though.
And yes, python will most definitely exit if there is no yes/no in the input. So it's probably just my habit to put the "else" there with an ERROR message