vtkCommonCorePython missing error in python3-paraview on Ubuntu 20

Question

I'm trying to use paraview scripting within python3 for Ubuntu 20.04.1 LTS. If I open python3 on the command line I get the error

$> python3
Python 3.8.2 (default, Jul 16 2020, 14:00:26) 
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from paraview.simple import *
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/paraview/simple.py", line 41, in <module>
    from paraview import servermanager
  File "/usr/lib/python3/dist-packages/paraview/servermanager.py", line 56, in <module>
    from paraview.modules.vtkPVServerImplementationCore import *
  File "/usr/lib/python3/dist-packages/paraview/modules/vtkPVServerImplementationCore.py", line 2, in <module>
    from . import vtkPVClientServerCoreCore
  File "/usr/lib/python3/dist-packages/paraview/modules/vtkPVClientServerCoreCore.py", line 2, in <module>
    from . import vtkPVCore
  File "/usr/lib/python3/dist-packages/paraview/modules/vtkPVCore.py", line 2, in <module>
    from . import vtkClientServer
  File "/usr/lib/python3/dist-packages/paraview/modules/vtkClientServer.py", line 3, in <module>
    from .vtkClientServerPython import *
ImportError: Failed to load vtkClientServerPython: No module named vtkmodules.vtkCommonCorePython
>>>

I have python3-paraview, paraview, paraview-dev, vtk7, python3-vtk7, etc installed from the synaptic installation manager. There are two files with vtkCommonCorePython inside the dist-packages directory :

/usr/lib/python3/dist-packages/vtk/vtkCommonCorePython.cpython-38-x86_64-linux-gnu.so
/usr/lib/python3/dist-packages/vtkmodules/vtkCommonCorePython.cpython-38-x86_64-linux-gnu.so

Searching the internet shows that other people have had similar problems, and solved it but including the paths to vtkCommonCorePython, but sys.path does include /usr/lib/python3/dist-packages, so vtkCommonCorePython should be found.

Can anybody see what might be missing in this case?

Many thanks! John

Answer 1

There are (or at least there were in previous versions) some slightly tricky conflicts between the vtk and paraview packages in python. I've found it's best to keep paraview for python in its own conda environment.

Assuming you have conda already, you should be able to get up and running with:

conda create -n paraview -c conda-forge paraview