I was a bit disappointed to learn that math-related Python packages don't seem to have an ln function. They all use log for the natural log and also have a log10.
You know what's even more dissapointing? bc - arbitrary precision calculator for linux shell uses 'l' for natural log, just a single letter.
And there's no other log function, so when you need logx(y) you write: ''l(y)/l(x)".