pkg-config python wrapper for building extensions with distutils

pkgconfig.py

import subprocess

def pkgconfig(*packages, **kw):
    """
    Query pkg-config for library compile and linking options. Return configuration in distutils
    Extension format.
    
    Usage: 
    
    pkgconfig('opencv')
    
    pkgconfig('opencv', 'libavformat')
    
    pkgconfig('opencv', optional='--static')
    
    pkgconfig('opencv', config=c)
    
    returns e.g.  
       
    {'extra_compile_args': [],
     'extra_link_args': [],
     'include_dirs': ['/usr/include/ffmpeg'],
     'libraries': ['avformat'],
     'library_dirs': []}
     
     Intended use:
          
     distutils.core.Extension('pyextension', sources=['source.cpp'], **c)
     
     Set PKG_CONFIG_PATH environment variable for nonstandard library locations.
    
    based on work of Micah Dowty (http://code.activestate.com/recipes/502261-python-distutils-pkg-config/)
    """
    config = kw.setdefault('config', {})
    optional_args = kw.setdefault('optional', '')
    
    # { <distutils Extension arg>: [<pkg config option>, <prefix length to strip>], ...}
    flag_map = {'include_dirs': ['--cflags-only-I', 2],
                'library_dirs': ['--libs-only-L', 2],
                'libraries': ['--libs-only-l', 2],
                'extra_compile_args': ['--cflags-only-other', 0],
                'extra_link_args': ['--libs-only-other', 0],
                }
    for package in packages:
        for distutils_key, (pkg_option, n) in flag_map.items():
            items = subprocess.check_output(['pkg-config', optional_args, pkg_option, package]).decode('utf8').split()
            config.setdefault(distutils_key, []).extend([i[n:] for i in items])
    return config