To generate .POT files, we are currently using the pology library, which has not updated to python3 (at the moment of writing this, there is only a stable branch on their repo).
pology has the further drawback of not being available on pip or usual distributions.
babel is a BSD-licensed python i18n library that also has support for .POT generation, which seems sufficient for our use-case.
It does require some slight tweaking to perform equivalently to our current setup, but nothing too major.
The generated POT messages are not in exactly the same order, but are compatible from what I can tell.
This also updates scripts to run with python3 (see also D2501).
I'm also bundling in a requirements.txt and a simple command-line argument to not-reparse everything.
I am further using Multiprocessing to generate the template files, which is up to [n_cores] faster.
I am unclear if we need to provide a LICENSE for this?