Programmable Filter Error

Hello everyone, I am new to paraview -and python, my question is the following:
I opened a pipeline dataset read by paraview from corresponding xdmf file, then I applied calculator filter twice to calculate two quantities. Then I use the filter group datasets to group together the results of the calculator filters. Next I would like to create a programmable filter just like the one described in the paraview guide. I follow the script instructions:

input0 = inputs[0]
dataArray = input0.PointData[“v”]/2.0
output.PointData.append(dataArray, “V_half”)

However the following error message appears that I wasn’t able to resolve:
NameError: name ‘RequestData’ is not defined. I choose my output as ,same as input, as described in the guide. Can someone please explain what is happening?
I am using paraview 5.7.

Are there any other error messages? Attached is a state file I tried to create using the Wavelet source and it seems to work without any issues.

foo.pvsm (339.5 KB)

Although I am late to reply, Thank you very much for sharing the file! Thanks to it I managed to find my error.