For documenting code, Sphinx has the advantage that you can use it for cool stuff like testing the sample code provided. See here: http://sphinx.pocoo.org/ext/doctest.html
But you won't get away with just docstrings. Good documentation also includes a high-level overview of the API, history of changes, a glossary of terms, etc...
It does have a slight learning curve, but it is very extensible while providing enough out-of-the-box already, and some people have been using it to write entire books.
That's exactly what I use too, it's not perfect but it gets you 95% of the way there. I didn't find it too hard to learn, I just picked up the examples and was on my way to writing the docs within a few minutes.
For documenting code, Sphinx has the advantage that you can use it for cool stuff like testing the sample code provided. See here: http://sphinx.pocoo.org/ext/doctest.html
But you won't get away with just docstrings. Good documentation also includes a high-level overview of the API, history of changes, a glossary of terms, etc...
It does have a slight learning curve, but it is very extensible while providing enough out-of-the-box already, and some people have been using it to write entire books.