setupext.py 文件源码

def check(self):
        if sys.platform == 'win32':
            check_include_file(get_include_dirs(), 'png.h', 'png')
            return 'Using unknown version found on system.'

        status, output = getstatusoutput("libpng-config --version")
        if status == 0:
            version = output
        else:
            version = None

        try:
            return self._check_for_pkg_config(
                'libpng', 'png.h',
                min_version='1.2', version=version)
        except CheckFailed as e:
            if has_include_file(get_include_dirs(), 'png.h'):
                return str(e) + ' Using unknown version found on system.'
            raise