Re: [Boost-users] [python::numpy] Access Violation when initializing numpy

Subject: Re: [Boost-users] [python::numpy] Access Violation when initializing numpy
From: Christian Henning (chhenning_at_[hidden])
Date: 2017-11-18 21:28:13

Ok, I figured it out. I had two sets of python libs installed, via the
Windows python installer and via vcpkg.

I hope the following items might help someone:

* the default python installation on Windows already comes with import libs
and the dlls.
* there is no need to built python with vcpkg not even for debug
configuration
* DONT set BOOST_DEBUG_PYTHON unless you want to debug python libs
* Ideally, there is no need to set PYTHONHOME and PYTHONPATH environmental
variables.

Regards,
Christian

On Sat, Nov 18, 2017 at 11:52 AM, Christian Henning <chhenning_at_[hidden]>
wrote:

> Hi all,
>
> On Windows 10 with Visual Studio 2017 I', trying to run the following code
> in x64 debug configuration:
>
> #include <iostream>
>
> #include <boost/python.hpp>
> #include <boost/python/numpy.hpp>
>
>
> namespace p = boost::python;
> namespace np = boost::python::numpy;
>
> int main()
> {
>     Py_Initialize();
>     np::initialize();
>
>     p::tuple shape = p::make_tuple(3, 3);
>     np::dtype dtype = np::dtype::get_builtin<float>();
>     np::ndarray a = np::zeros(shape, dtype);
>
>     return 0;
> }
>
>
> In the line
>
> np::initialize();
>
> I'm getting a
>
> Exception thrown at 0x0000000066E43B15 (python36.dll) in test.exe:
> 0xC0000005: Access violation reading location 0x0000000000000025. occurred
>
> Inside boost::python::numpy::intialize() the exception is thrown when
> trying to execute the line:
>
> PyObject *numpy = PyImport_ImportModule("numpy.core.multiarray");
>
>
> Does anyone know why that would happen or how to debug the issue further?
>
> I have installed all packages via pip and executed the python code as
> described in https://www.scipy.org/getting-started.html.
>
> Thanks ahead!
> Christian
>
>