Python Scripting - how do you select surface points

Thx to the help I now now howto select objects (not only their guid) with Python. So now I wonder - if I have surface as object, how do I get points that define it?

It seems I’ll need it for some of the scripts I have in mind - for example to make selected surface flat as it seems I can’t use “0” as a parameter for Scale1D (it works only with gumball).