import cadquery as cq
w0=cq.Workplane('YZ',origin=(0,0,0))
w1=cq.Workplane('ZX',origin=(0,-9,0))
r=w0.workplane(offset=-50/2).moveTo(-13,0).cylinder(50,34).union(w0.workplane(offset=13/2).moveTo(-12.5,0).box(41,14,13)).union(w0.sketch().segment((22,0),(24,-1)).arc((24,4),(23,8)).close().assemble().finalize().extrude(50)).union(w1.sketch().segment((-27,11),(-9,11)).segment((-9,-9)).segment((9,-9)).segment((9,11)).segment((27,11)).segment((27,21)).segment((9,21)).segment((9,42)).segment((-9,42)).segment((-9,21)).segment((-27,21)).close().assemble().finalize().extrude(56))