import cadquery as cq
w0=cq.Workplane('YZ',origin=(6,0,0))
r=w0.workplane(offset=-31/2).moveTo(9,3).cylinder(31,12).union(w0.sketch().push([(-34,-26.5)]).rect(20,47).reset().face(w0.sketch().segment((7,49),(44,31)).segment((44,32)).segment((7,50)).close().assemble()).finalize().extrude(19))