The functions in the package are documented. The documentation in nicely formatted form can be obtained by running sphinx.
First of all, install sphinx and a good theme:
pip install sphinx
pip install pydata_sphinx_theme
In the pystran folder, run
sphinx-apidoc -o docs/source pystran/ -e
which will create the .rst files
Then, go into the pystran/docs folder,
cd docs/
and run
sphinx-build.exe -M html source build
Or, in one shot (cd docs; sphinx-build.exe -M html source build).
Now the documentation will be in pystran/docs/build/html.
Double click the index.html file in that folder.