[Paraview] Error calling UpdatePipeline from PythonCalculator

[Ian Krukow]

Hi all,

I am just starting to use the Python Calculator, but I get an error 
whenever I call UpdatePipeline. I use ParaView 4.1.0 32-bit binaries on 
Windows 7 with the built-in pvpython.

The Calculator works fine with the GUI, and also with the Python Shell 
(no error there), but not with a pvpython script like this example:

from paraview.simple import *
sphere = Sphere()
pycalc = PythonCalculator()
pycalc.Expression = 'inputs[0].PointData["Normals"]'
pycalc.UpdatePipeline()

On execution of the last command, I get:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named paraview

If I go into debug mode with pdb, I can execute UpdatePipeline a second 
time, and I do NOT get an error (only one error the first time).

Can somebody tell me, what is wrong?

Kind regards
Ian