I could use some assistance

My final project in a python class is to calculate the distance between 2 lat/long points. My code is really just managing the input & output portions, while using existing code (properly credited) in a function to do the actual calculations.

I've got it working using 1 type of calculation (Haversine), but I want to use a different formula, as they give slightly different results. Having said all that - my problem is - the only source I can find for the calculation I want is written in JavaScript.

Im just starting to wrap my brain around Python & Im not good enough at math to figure out what is calculation and what is JavaScript syntax..

Does anyone know a source for Rhumb Line distance calculation in Python or

Does anyone know a tool that works for doing the translation, or

Can anyone help me with the translation?

Sorry for being so long winded.