[Paraview] Step interpolation in keyframes via Python?

[Marc A. Kastner]

Hello,

I am trying to write a python script for a project where I need to 
animate stuff. When doing it manually, I usually use the Step 
interpolation feature between keyframes. How do I get such a behaviour 
with a Python skript? I tried following code snipplet in Python shell:

keyframe = CompositeKeyFrame()
keyframe.Interpolation = 'Step' (This attribute is default 'Ramp' so I 
thought this would work)

But it says: "ValueError: Step is not a valid value.".

Thanks in advance.

- Marc A. Kastner