I tried this without success:
import os
import rhinoinside
try:
rhinoinside.load()
except:
pass
import System
import Rhino
file = r'..\3dm_files\a.3dm'
doc = Rhino.RhinoDoc.OpenHeadless(file)
for o in doc.Objects:
# o == https://developer.rhino3d.com/api/rhinocommon/rhino.docobjects.instanceobject
if o.Geometry.ObjectType == Rhino.DocObjects.ObjectType.Brep:
print("Brep")
print(o.Geometry.Transform.Translation)
doc.Dispose()