Python 3.8 wrapping support?


I am trying to compile VTK 8.2.0 on Windows 10 64bit, Python 3.8.1 64bit, Visual Studio 2015 Update 3.

A simple CMake configuration that has worked well with VTK 8.1.2 and Python 3.6 is now throwing hundreds of errors at compile time of the kind:

48>Y:\Libraries_Requiring_Compile\vtk-8.2.0\vtk-8.2.0-bin\Wrapping\Python\vtkSphericalTransformPython.cxx(231): error C2440: ‘initializing’: cannot convert from ‘nullptr’ to ‘Py_ssize_t’

Does anyone have similar problems? I did not find anything particular about this in this section of VTK Discourse, and some info on a general search, dating Jan 2019, saying that wrapping for Python 3.8 was not working at the time.

Can anyone kindly confirm what is the situation with wrapping Python 3.8?

Thanks and Best Regards,


Hi Andrea,

The release branch of VTK contains fixes for Python 3.8. The release branch is what would have become VTK 8.2.1.


Hi David,

Thanks for this answer. Does it mean also that there will not be a version 8.2.1 ?

Best Regards, thanks,


@Dave_DeMarle is a 8.2.1 release still out of the question?

I know that the intent was to move forward with the 9.0 release, but realistically I can’t see VTK 9 coming out any time soon.

Yes. I still don’t intend to make an 8.2.1.

Why are you thinking a 9 is not realistic? If there is something fundamentally wrong with master, I might change my answer of course.

I don’t think these fixes landed in release since they were deemed as clang-tidy noise fixes. I wasn’t aware that VS2015 was making these into errors. You’ll need these patches:


Thanks for the info.

Best Regards,