How to statically link a library when compiling a python module extension

Question

I would like to modify a setup.py file such that the command \"python setup.py build\" compiles a C-based extension module that is statically (rather than dynamically) linke

Answer 1

6 - 7 years later, static linking with Python extensions is still poorly documented. This Q/A helped for me to find the solution but as it is now, it is not clear.

On Linux / Unix

Static libraries are linked just as object files and should go with the path into extra_objects.

On Windows

The compiler sees if the linked library is static or dynamic and the static library name goes to the libraries list and the directories to library_dir

Solution for both platforms

For the example below, I will use the same library scenario as OP, linking igraph static and z, xml2 and gmp dynamic. This solution is a bit hackish, but at least does for each platform the right thing.

static_libraries = ['igraph']
static_lib_dir = '/system/lib'
libraries = ['z', 'xml2', 'gmp']
library_dirs = ['/system/lib', '/system/lib64']

if sys.platform == 'win32':
    libraries.extend(static_libraries)
    library_dirs.append(static_lib_dir)
    extra_objects = []
else: # POSIX
    extra_objects = ['{}/lib{}.a'.format(static_lib_dir, l) for l in static_libraries]

ext = Extension('igraph.core',
                 sources=cmf_files,
                 libraries=libraries,
                 library_dirs=library_dirs,
                 include_dirs=include_dirs,
                 extra_objects=extra_objects)

On MacOS

I guess this works also for MacOS (using the else path) but I have not tested it.