Python C extension help

[elmarcia]

Hi, i'm learning python C extensions and want to implement my own dynamic stack function, i made it work but don't know how to return a non-tuple value.

Am i missing something or what, i used as reference python's collection module but i can't figure out what i'm doing wrong.
I don't want to put python code to manage the tuple return i need it to be embedded in c code. (also should return any data type)

My module:


Python collection module (deque):


My stack module

 Spoiler

#include "Python.h"
#include "structmember.h"

/* Type definition */
typedef struct {
    PyObject_HEAD
    int current_size;
    int top;
    PyObject **content;
} Stack;

static PyTypeObject StackType;


//create stack instance when reference from python
static PyObject *
Stack_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
{
   Stack *stack;
 
    stack = (Stack *)type->tp_alloc(type, 0);
    if (stack == NULL)
        return NULL;
    Py_SIZE(stack) = 0;
    stack->top = -1;
    stack->current_size = 2;
    stack->content = PyMem_Malloc(sizeof(PyObject) * stack->current_size);
    if (stack->content != NULL) {
        return (PyObject *)stack;
    }
    PyErr_NoMemory();
    return NULL;
}

static int
Stack_tp_clear(Stack *self)
{
    Py_CLEAR(self->content);
    return 0;
}

//resize stack to 2 times its current size
static PyObject* Stack_resize(Stack * self){
        PyObject ** resized = PyMem_Malloc(sizeof(PyObject) * self->current_size);
        if(resized == NULL){
            PyErr_NoMemory();
            return NULL;
        }
        memcpy(resized, self->content, sizeof(PyObject) * self->top + 1);
        PyMem_Free(self->content);
        self->current_size = self->current_size * 2;
        self->content = resized;
        Py_RETURN_NONE;
}

//push value to stack
static PyObject* Stack_setContent(Stack * self,PyObject * item){
   Py_INCREF(item);
    self->top = self->top + 1;
    self->content[self->top] = item;
    if(self->top == self->current_size - 1){
        return Stack_resize(self);
    }
    Py_RETURN_NONE;
}

//pop value from stack
static PyObject * Stack_get(Stack * self){
    if(self->top < 0){
         PyErr_SetString(PyExc_IndexError, "pop from an empty stack");
         return NULL;
    }
    PyObject *m = self->content[self->top];
    self->top = self->top - 1;
    return m;
}

//clear memory garbage collector
static int
Stack_tp_traverse(Stack *self, visitproc visit, void *arg)
{
    int i ;
    for(i = 0;i<self->top;i++)
        Py_VISIT(self->content[i]);
    return 0;
}

//dealloc memory
static void
Stack_tp_dealloc(Stack *self)
{
    Stack_tp_clear(self);
    Py_TYPE(self)->tp_free((PyObject *)self);
}


 static PyMethodDef Stack_methods[] = {
     {"pop",(PyCFunction)Stack_get,METH_NOARGS,"Lista los metodos exportados del modulo"},
     {"push",(PyCFunction)Stack_setContent,METH_VARARGS,"genera una lista de numeros aleatorios o un numero aleatorio"},
     {NULL,NULL,0,NULL}
 };

/* NO USE
static PyMemberDef Stack_members[] = {
    {"content", T_OBJECT_EX, offsetof(Stack, content), 0, "content"},
    {NULL}
};
*/

static PyTypeObject StackType = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "foo.stack",                                /*tp_name*/
    sizeof(Stack),                              /*tp_basicsize*/
    0,                                          /*tp_itemsize*/
    (destructor)Stack_tp_dealloc,               /*tp_dealloc*/
    0,                                          /*tp_print*/
    0,                                          /*tp_getattr*/
    0,                                          /*tp_setattr*/
    0,                                          /*tp_compare*/
    0,                                          /*tp_repr*/
    0,                                          /*tp_as_number*/
    0,                                          /*tp_as_sequence*/
    0,                                          /*tp_as_mapping*/
    0,                                          /*tp_hash */
    0,                                          /*tp_call*/
    0,                                          /*tp_str*/
    0,                                          /*tp_getattro*/
    0,                                          /*tp_setattro*/
    0,                                          /*tp_as_buffer*/
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /*tp_flags*/
    0,                                          /*tp_doc*/
    (traverseproc)Stack_tp_traverse,            /*tp_traverse*/
    (inquiry)Stack_tp_clear,                    /*tp_clear*/
    0,                                          /*tp_richcompare*/
    0,                                          /*tp_weaklistoffset*/
    0,                                          /*tp_iter*/
    0,                                          /*tp_iternext*/
    Stack_methods,                              /*tp_methods*/
    0,                                          /*tp_members*/
    0,                                          /*tp_getsets*/
    0,                                          /*tp_base*/
    0,                                          /*tp_dict*/
    0,                                          /*tp_descr_get*/
    0,                                          /*tp_descr_set*/
    0,                                          /*tp_dictoffset*/
    0,                                          /*tp_init*/
    0,                                          /*tp_alloc*/
    Stack_tp_new,                               /*tp_new*/
};


static struct PyModuleDef fooModule = {
    PyModuleDef_HEAD_INIT,
    "foo",
    "DOCS",
    -1,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL
};

/* Module init */
PyMODINIT_FUNC
PyInit_foo(void)
{
   PyObject *m;
    m = PyModule_Create(&fooModule);
    if (m == NULL)
        return NULL;
      
    if (PyType_Ready(&StackType) < 0)
        return NULL;
    Py_INCREF(&StackType);
    PyModule_AddObject(m, "stack", (PyObject *)&StackType);
    return m;
}

collections module:

[sk8land​]

Change line

{"push",(PyCFunction)Stack_setContent,METH_VARARGS,"..."},

into

{"push",(PyCFunction)Stack_setContent,METH_O,"..."},

[elmarcia]

Originally Posted by sk8land​

Change line

{"push",(PyCFunction)Stack_setContent,METH_VARARGS,"..."},

into

{"push",(PyCFunction)Stack_setContent,METH_O,"..."},

LOL, i read all examples but can't find that, thx dude!