import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,50))
r=w0.sketch().segment((-31,-41),(50,-41)).segment((50,24)).segment((17,24)).arc((-40,29),(-31,-28)).close().assemble().reset().face(w0.sketch().segment((3,-40),(25,-40)).segment((25,-10)).segment((12,-10)).arc((-35,24),(3,-19)).close().assemble(),mode='s').finalize().extrude(-100)