import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,18))
r=w0.sketch().segment((-100,-89),(100,-89)).segment((100,89)).segment((-100,89)).segment((-100,18)).arc((-95,15),(-100,13)).close().assemble().rect(42,150,mode='s').finalize().extrude(-37)