Any function in Rhino Python that returns the GUIDs of all objects currently active in a Rhino window?

Is there any function (or can anyone recommend methods) that will return the GUIDs of all/specific objects currently active in the Rhino window? Basically I am working on a script that requires that parts of the previous drawing to be deleted, but not the whole drawing.

You might try rs.VisibleObjects()


Thanks! This is exactly what I was looking for.