Cython function signatures in Sphinx

This is a demonstration of how to use Cython's embedsignature compiler directive to show Cython function signatures in Sphinx documentation. The main "magic" here is in setup.py where we actually specify the compiler directive.

The demonstration involves creating a Cython-based module along with a pure Python module and then rendering their documentation in Sphinx via autodoc. The Sphinx-generated HTML contains function signature information for both the pure Python functions as well as those defined in Cython.

Running the demo

This is intended to be run in a Python 2.7 environment (virtual or otherwise), though it will likely work in Python 3.x as well. You'll need tools like make and a C compiler - all of the stuff you normally need for Cython and Sphinx development - to complete the steps.

First install the necessary requirements:

pip install -r requirements.txt

To build the cython extension:

python setup.py build_ext --inplace

Then build the sphinx docs:

make clean && make html

The resulting documentation will be in build/html/index.html.