Generating wrapper code for a c++ library to be used in python

Question

I am creating a simulation tool in python and require a c++ library. How do I go about interfacing the library with python? The library is large but I only want to call a few functions and class member functions.

So far I have tired using ctypes and SWIG on smaller bits of c++ code just to familiarize myself with the process.

With ctypes the c++ library must already be compiled into a shared library, which is not a problem. I have used ctypes to call c++ function from a shared library but can you use ctypes to call class member functions?

If I use SWIG must I include all the header files of the c++ library in the interface file or only the ones that include the function I need?

Answer 1

ctypes can call C interfaces, or C++ interfaces that are extern "C" , but it does not understand C++-specific classes such as std::string or member functions.

With SWIG, you may include only the headers in the SWIG interface file that you want to expose to Python. For example:

%module example

%{  
// This section is copied into the wrapper so the generated code can compile.
// No wrappers are generated from this.
#include "myheader1.h"
#include "myheader2.h"
%}

%include "myheader1.h"  // Wrap all functions directly declared in this header.    
int myfunc(int a, int b);  // Wrap only this one function in myheader2.h.