NULL结果，PyObject_Call中没有错误

Question

I'm currently coding a Python C-Extension to perform some calculations in C instead of Python. It works just fine, I already got some nice results, but the point is, I get the following error:

NULL result without error in PyObject_Call

It occurs sometimes, not always, when I want to create an instance of the "C Python Object" I created. The call looks something like the following:

import c_class

obj = c_class.dummy(arg1, arg2, arg3);

Does anyone have any suggestions? I don't know where this error comes from, since it works from time to time.. I'm kind of lost here.

Answer 1

When you return NULL from ac function exposed to python you must set the error message before, since returning NULL means an error happened.

If an error happened and you are returning NULL because of that then, use PyErr_SetString() , if no error happened, then use

Py_RETURN_NONE;