Hi @lassoan, that is the extension that I developed 
I am trying to extend it for a different problem and also to simplify the installation. I have lost my previous development environment and it was quite difficult to install back then. I was hoping there may be a better way to install the Python modules. Last time I did it like this:
However, I have now installed FEniCS binaries instead of from source. I would like to just install the Python modules inside Slicer so I can import fenics or dolfin inside my extension module.
Here is the fenics package on pypi: