Numpy/capi Error With Import_array() When Compiling Multiple Modules

I am trying to compile a C++ module to use in scipy.weave that is composed of several headers and source C++ files. These files contain classes and methods that extensively use the

Solution 1:

I had a similar problem, as the link you've posted points out, the root of all evil is that the PyArray_API is defined static, which means that each translation unit has it's own PyArray_API which is initialized with PyArray_API = NULL by default. Thus import_array() must be called once for every *.cpp file. In your case it should be sufficient to call it in pycapi_utils.cpp and also once in model.cpp. You can also test if array_import is necessary before actualy calling it with:

if(PyArray_API == NULL)
{
    import_array(); 
}

Solution 2:

So apparently if I include in the pycapi_utils module a simple initialization routine such as:

//pycapi_utils.h
...
...
voidinit_numpy();

//pycapi_utils.cpp
...
...
voidinit_numpy(){
    Py_Initialize;
    import_array();
}

and then I invoke this routine at the beginning of any function / method that uses Numpy objects in my C code, it works. That is, the above code is edited as:

//pycapi_utils.cpp
...
...
PyObject* array_double_to_pyobj(...){
    init_numpy();
    ...
    ...
}


//model.cpp
...
...
PyObject* simulate(...){
    init_numpy();
    ...
    ...
}

My only concern at this point is whether there is a way to minimize number of calls to init_numpy(), or regardless I have to call it from any function that I define within my CPP modules that uses Numpy objects...