import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,18,0))
r=w0.sketch().push([(-28,-26)]).rect(44,46).reset().face(w0.sketch().segment((13,-3),(20,-3)).segment((20,2)).arc((32,49),(13,5)).close().assemble()).finalize().extrude(-36)