Page 157
example.c
#define PY_SSIZE_T_CLEAN
#include <Python.h>
static PyObject *exampleFunction(PyObject *self, PyObject *args)
{
// example function code
}
static PyMethodDef AddMethods[] = {
{"exampleFunction", exampleFunction, METH_VARARGS, "an example"},
{NULL, NULL, 0, NULL} // sentinel
};
static PyObject *myFunc(PyObject *self, PyObject *args)
{
printf("hello world\n");
Py_RETURN_NONE;
}
static PyObject *myFunc2(PyObject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
{
for (int i = 0; i < nargs; i++)
{
const char *myString = PyUnicode_AsUTF8(args[i]);
printf("%s\n", myString);
}
Py_ssize_t nKwds = PyTuple_Size(kwnames);
for (int i = 0; i < nKwds; i++)
{
const char *myValue = PyUnicode_AsUTF8(args[i + nargs]);
const char *myKeyword = PyUnicode_AsUTF8(PyTuple_GetItem(kwnames, i));
printf("Keyword = %s, Value = %s \n", myKeyword, myValue);
}
Py_RETURN_NONE;
}
static PyMethodDef myFunc_def = {
"myFunc",
myFunc,
METH_VARARGS,
"the doc string"};
static PyMethodDef myFunc2_def = {
"myFunc2",
(PyCFunction)myFunc2,
METH_FASTCALL | METH_KEYWORDS,
"the doc string"};
static struct PyModuleDef myModule = {
PyModuleDef_HEAD_INIT,
"example",
"C library to test API",
-1,
NULL};
PyMODINIT_FUNC PyInit_example(void)
{
PyObject *m = PyModule_Create(&myModule);
if (m == NULL)
return NULL;
// Add a int
PyObject *myValue = PyLong_FromLong(42);
PyModule_AddObject(m, "myValue", myValue);
// Add a list
PyObject *myList = PyList_New(0);
PyModule_AddObject(m, "myList", myList);
// Add a function
PyObject *myPyFun = PyCFunction_New(&myFunc_def, m);
PyModule_AddObject(m, "myFunc1", myPyFun);
// Add a fastcall function
PyObject *myPyFun2 = PyCFunction_New(&myFunc2_def, m);
PyModule_AddObject(m, "myFunc2", myPyFun2);
//Add a function in another module
PyObject *math=PyImport_ImportModule("math");
PyObject *mathdict = PyModule_GetDict(math);
PyObject *myFunction = PyDict_GetItemString(mathdict, "sqrt");
PyModule_AddObject(m, "myFunc3", myFunction);
return m;
}
test.py
import example
print("module constant",example.myValue)
example.myValue=43
print("module constant",example.myValue)
print(example.myList)
example.myList.append("spam")
print(example.myList)
print(example.myFunc1())
example.myFunc2("Hello","World",MyKeyWord="myValue")
print(example.myFunc3(2))
print(example.myFunc3.__name__)
Page 160
example.c
#define PY_SSIZE_T_CLEAN
#include <Python.h>
int exec(PyObject *m)
{
PyObject *myValue = PyLong_FromLong(42);
PyModule_AddObject(m, "myValue", myValue);
return 0;
}
PyObject *create(PyObject *spec, PyModuleDef *def)
{
PyObject *res=PyObject_GetAttrString(spec,"origin");
printf("%s\n",PyUnicode_AsUTF8(res));
PyObject *m= PyModule_New("example");
return m;
}
PyModuleDef_Slot twoPhase[] = {
{Py_mod_create, create},
{Py_mod_exec, exec},
{0, 0}};
static struct PyModuleDef myModuledef = {
PyModuleDef_HEAD_INIT,
"example",
"C library to test API",
0,
NULL,
twoPhase};
PyMODINIT_FUNC PyInit_example(void)
{
return PyModuleDef_Init(&myModuledef);
}
test.py
import example
print(example.myValue)
Page 164
example.c
#define PY_SSIZE_T_CLEAN
#include <Python.h>
struct myData
{
int count;
char name[20];
};
static struct myData myModuleData = {42, "spam"};
static PyObject *myFunc(PyObject *self, PyObject *args)
{
printf("module data %d , %s\n", myModuleData.count, myModuleData.name);
myModuleData.count++;
struct myData *myModData = (struct myData *)PyModule_GetState(self);
printf("module data %d , %s\n", myModData->count, myModData->name);
myModData->count++;
Py_RETURN_NONE;
}
static PyMethodDef myFunc_def = {
"myFunc",
myFunc,
METH_VARARGS,
"the doc string"};
int exec(PyObject *m)
{
struct myData *myModData = (struct myData *)PyModule_GetState(m);
myModData->count = 42;
strcpy(myModData->name, "spam");
PyObject *myValue = PyLong_FromLong(42);
PyModule_AddObject(m, "myValue", myValue);
PyObject *myPyFun = PyCFunction_New(&myFunc_def, m);
PyModule_AddObject(m, "myFunc", myPyFun);
return 0;
}
PyObject *create(PyObject *spec, PyModuleDef *def)
{
PyObject *res = PyObject_GetAttrString(spec, "origin");
printf("%s\n", PyUnicode_AsUTF8(res));
PyObject *m = PyModule_New("example");
return m;
}
void freeModule(void *m){
struct myData *myModData = (struct myData *)PyModule_GetState(m);
PyMem_Free(myModData);
}
PyModuleDef_Slot twoPhase[] = {
{Py_mod_create, create},
{Py_mod_exec, exec},
{0, 0}};
static struct PyModuleDef myModuledef = {
PyModuleDef_HEAD_INIT,
"example",
"C library to test API",
sizeof(struct myData),
NULL,
twoPhase,
NULL,
NULL,
freeModule};
PyMODINIT_FUNC PyInit_example(void)
{
return PyModuleDef_Init(&myModuledef);
}
test.py
import example
example.myFunc()
example.myFunc()
