Recompile the modified source code for opencv python

edit

I'm currently trying to expose different internal c++ function to python, for example, to expose the elbp function, I opened the facerec.hpp and put the following code

CV_EXPORTS_W Mat elbp(InputArray src, int radius, int neighbors);

after namespace while removing the static before the wrapper function:

static Mat elbp(InputArray src, int radius, int neighbors) {
Mat dst;
elbp(src, dst, radius, neighbors);
return dst;}

After this, what I did was to run the cmake in the opencv build directory and then make the whole opencv again,the whole process took like 2 hour(since im doing it on a raspberry pi) which is really painful. I dont want to switch to c++ atm, is there any other way to simply expose the internal c++ function(or do some modification on the existing function) without recompile the whole opencv?

I'm quite new to both Linux and opencv，i would be really appreciated if anyone can help.....