[Tutor] Refcount in C extensions

[Izz ad-Din Ruhulessin]

Hello,

I am writing a Python C extension and I have some trouble understanding how
reference counting works exactly. Though I think I understand the practice
on simple operations (see my question at stackoverflow:
http://stackoverflow.com/questions/4657764/py-incref-decref-when), but on
more "complex" operations I cannot quite grasp it yet.

For example, in the following helper function, do I need to DECREF or are
all the references automatically destroyed when the function returns?

double Py_GetAttr_DoubleFromFloat(PyObject *obj, const char *attr)
{
if ((PyObject_GetAttrString(obj, attr) == False) ||
(PyObject_HasAttrString(obj, attr) == False)) {
return -9999.0;
}

return PyFloat_AsDouble(PyNumber_Float(PyObject_GetAttrString(obj, attr)));
}

Please share your thoughts, thanks in advance, kind regards,

Izz ad-Din
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