JS gives you wrong answers silently when thigns go sideways since for the original browser use case, they didn't want scripts to ever stop execution. It's the opposite of Python in this respect.

You are going to have to give more support for those assertions. I write Python every day, and never would I call it a good candidate for the clankers. Pretty much any dynamic language would be ruled out, as there is too much implicit logic which makes it harder to understand what is happening.