The best thing to do is to take a look at the Cython docs (http://cython.org/ http://cython.org/) and check out some of the whitepapers they have posted. There

The best thing to do is to take a look at the Cython docs (http://cython.org/ http://cython.org/) and check out some of the whitepapers they have posted. There is also a bunch of cython code on github. If you search "cdef extern" you should find examples where other people have wrapped external c libraries.