import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-10,0))
r=w0.sketch().arc((25,-12),(27,0),(25,12)).close().assemble().finalize().extrude(-40).union(w0.sketch().segment((-27,-18),(-26,-18)).segment((-26,-33)).segment((6,-33)).segment((6,-18)).segment((7,-18)).segment((7,18)).segment((6,18)).segment((6,33)).segment((-26,33)).segment((-26,18)).segment((-27,18)).close().assemble().finalize().extrude(60))