Error on running trace from the CMD interface.

Hello everyone,
I created a basic trace which creates a sphere with a simple half-plane clip. The trace runs fine with the python shell within the GUI framework. However, when I try to run the file using PvPython as instructed in https://www.paraview.org/Wiki/PvPython_and_PvBatch, an attribute error throws up:


Help in this regard would be appreciated.
Thanks,
Sounak
My OS: 64-bit Microsoft Windows
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