Extracting Material Names from Plaxis Output using Python

Hi, I have a question regarding the extraction of material information from Plaxis Output.

Following the example given by this article: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45443/material-lists-in-plaxis-python , I tried to extract a list of soil material names in the model by modifying the code like so: 

Soil_list = [mat.MaterialName.value for mat in g_i.Materials[:] if mat.TypeName.value == 'SoilMat']

This worked perfectly in Plaxis Input. However, when I tried to apply the same code with Plaxis Output scripting, the error "Requested attribute 'TypeName' is not present" occurred. I further tried other ways like:

Soil_list = [mat.Name for mat in g_o.Soils]

But this only returned a list of ['Soil_1', 'Soil_2', ...], which is not what I want.

So my question is: Is there any python code I can use to extract material names from Plaxis Output?

Thank you.