Stop a function if the list it needs is empty

[Pedroski55]

I have a function to take theWords, a list of words or phrases, and make an html table with them. Works OK.

Sometimes, I forget to click the button "get the words", so the words list is empty. Nothing happens, no error.

I'd like to catch that with something like:

if len(theWords) == 0:
    echoMessage('You forgot the words Dummkopf!)
    exit()

What is the best way to jump out of a function if a condition is not met?