Maya: Select -X Half of Object using object space pivot orientation in Maya Python?

Hey TA.org,

Forgive me I’m quite new to scripting and this seems really complicated… not sure where to start.

Is it possible to select vertices in the -x direction of an objects current pivot orientation?

I’m trying to use that function in delete half and mirror, delete half and mirror instance scripts

I looked at polyselectscontraints and xform but I don’t think they do what I want…