[rciorba]

> I think PyPy is switching to cffi as the way to connect to C code so most native code "just works" now.

As far as I know extensions need to be written for cffi specifically.

cffi is a newer way of writing C extensions, developed by the PyPy project. It was designed to have a smaller&cleaner interface to let you call C code from Python. Here's Armin Rigo talking about it at EuroPython: https://www.youtube.com/watch?v=ejUzVcvTLgI

The CPython way of writing extensions is documented here: https://docs.python.org/3/extending/extending.html It seems to require you to deal with the internals of the CPython interpreter (deal with PyObject structs, reference counting, etc).

I know PyPy has some support for CPython extensions, but it has to emulate some internals and it's slower as a result.