import salome
salome.salome_init_without_session()
import GEOM
from salome.geom import geomBuilder
import salome_notebook
gg = salome.ImportComponentGUI("GEOM")
notebook = salome_notebook.notebook
notebook.set("Length", 150)
notebook.set("Width", 100)
box = geompy.MakeBoxDXDYDZ("Length", "Width", 200)
id_box = geompy.addToStudy(box,"Box")
gg.createAndDisplayGO(id_box)
gg.setDisplayMode(id_box,1)
Download this script