import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-5,0))
r=w0.workplane(offset=-45/2).moveTo(-30,-39.5).box(12,11,45).union(w0.sketch().segment((-12,14),(36,14)).segment((36,45)).segment((31,45)).arc((27,35),(21,26)).segment((21,15)).segment((3,15)).segment((3,17)).arc((-5,16),(-12,17)).close().assemble().finalize().extrude(55))