C扩展案例

spammoudle.c 文件

#include <Python.h>


static PyObject *SpamError;


static PyObject * spam_system(PyObject *self, PyObject *args) {
    const char *command;
    int sts;

    if (!PyArg_ParseTuple(args, "s", &command))
        return NULL;
    sts = system(command);
    if (sts < 0) {
        PyErr_SetString(SpamError, "System command failed");
        return NULL;
    }
    return PyLong_FromLong(sts);
}


static PyMethodDef SpamMethods[] = {
    {"system",  spam_system, METH_VARARGS, "Execute a shell command."},
    {NULL, NULL, 0, NULL}        /* Sentinel */
};


static struct PyModuleDef spammodule = {
    PyModuleDef_HEAD_INIT,
    "spam",   /* name of module */
    NULL, /* module documentation, may be NULL */
    -1,       /* size of per-interpreter state of the module,
                 or -1 if the module keeps state in global variables. */
    SpamMethods
};


PyMODINIT_FUNC PyInit_spam(void) {  // non-static
    PyObject *m;

    m = PyModule_Create(&spammodule);
    if (m == NULL)
        return NULL;

    SpamError = PyErr_NewException("spam.error", NULL, NULL);
    Py_INCREF(SpamError);
    PyModule_AddObject(m, "error", SpamError);
    return m;
}


int main(int argc, char *argv[]) {
    wchar_t *program = Py_DecodeLocale(argv[0], NULL);
    if (program == NULL) {
        fprintf(stderr, "Fatal error: cannot decode argv[0]\n");
        exit(1);
    }

    /* Add a built-in module, before Py_Initialize */
    PyImport_AppendInittab("spam", PyInit_spam);

    /* Pass argv[0] to the Python interpreter */
    Py_SetProgramName(program);

    /* Initialize the Python interpreter.  Required. */
    Py_Initialize();

    /* Optionally import the module; alternatively,
       import can be deferred until the embedded script
       imports it. */
    PyImport_ImportModule("spam");

    PyMem_RawFree(program);
    return 0;
}

setup.py 文件

from distutils.core import setup, Extension


module = Extension('spam', sources = ['spammoudle.c'])


setup (
    name = 'PackageName',
    version = '1.0',
    description = 'This is a demo package',
    ext_modules = [module],
)

shell 安装:

python setup.py build   # 安装
> running build
> running build_ext
> building 'spam' extension
> /usr/bin/clang -fno-strict-aliasing -Wsign-compare -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -arch i386 -arch x86_64 -g -I/Library/Frameworks/Python.framework/Versions/3.6/include/python3.6m -c spammoudle.c -o build/temp.macosx-10.6-intel-3.6/spammoudle.o
> creating build/lib.macosx-10.6-intel-3.6
> /usr/bin/clang -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-3.6/spammoudle.o -o build/lib.macosx-10.6-intel-3.6/spam.cpython-36m-darwin.so
> ld: warning: The i386 architecture is deprecated for macOS (remove from the Xcode build setting: ARCHS)
> ld: warning: ignoring file /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd, missing required architecture i386 in file /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd

导入使用

进入/build/lib.macosx-10.6-intel-3.6/ 找到 spam.cpython-36m-darwin.so，同级目录下import spam 导入到py文件中使用