import cadquery as cq
w0=cq.Workplane('YZ',origin=(-3,0,0))
r=w0.sketch().push([(-20,-12)]).circle(18).push([(-7.5,-5.5)]).rect(1,1,mode='s').push([(18,-30)]).circle(20).finalize().extrude(-30).union(w0.sketch().segment((-12,27),(-5,27)).segment((7,27)).segment((14,27)).segment((14,50)).segment((7,50)).segment((-5,50)).segment((-12,50)).close().assemble().push([(5,28)]).circle(1,mode='s').finalize().extrude(36))