[SciPy-Dev] Understanding source of docs, source file ".py" or ".rst" file

[Vincent Davis]

There are two sets of docs for scipy.constants.constants, that in the
source constants.py and that in that in
scipy/doc/source/constants.rst.
The rst file is what is used on the website but I am not sure how to
(can you) view it from an interactive py session.
Is it necessary to maintain both?
Or more generally whats the protocol for how and why this is done.

Thanks
Vincent