import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,-15))
r=w0.sketch().circle(50).reset().face(w0.sketch().segment((-44,-19),(-39,-19)).segment((-39,-20)).segment((-15,-20)).segment((-15,9)).segment((-16,9)).segment((-16,11)).segment((-44,11)).close().assemble(),mode='s').finalize().extrude(30)