Python AZNB on_player_message Problem

Micah-M was helping me out over here: https://educommunity.minecraft.net/hc/en-us/community/posts/4409575404436-Python-Notebooks-MegaJump

and I was having some fun coding. I ran into my first ever infinite loop on Minecraft today! The output the first time looks right, but may not include a second parameter (like a jump height.) The second time, it dies a sad death.

My best work with this so far is giving me the impression that somehow the chat message calls this procedure *twice* - once with the simple chat message, and another time with a [user name] appended. In any event (no pun intended!!!) that's how it seems, since sometimes the echo produces a username, and sometimes not. 

My full code is my attempt to draw out the int value from a chat text like "jump 5" - and I am making progress, although I wouldn't call it a magnificent success at the moment. =] But while I cannot even get the data from this little guy to work consistently, I am a bit stuck!

To clarify that green comment, the code runs once, and the second time throws the error. Ditch line four, and live forever! =] I did check known issues, btw.