import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,2,0))
w1=cq.Workplane('YZ',origin=(15,0,0))
r=w0.sketch().push([(0,17)]).circle(20).circle(18,mode='s').finalize().extrude(-52).union(w1.sketch().segment((21,-15),(50,-15)).segment((50,9)).segment((24,9)).arc((-13,3),(21,-14)).close().assemble().finalize().extrude(-52))