import cadquery as cq
w0=cq.Workplane('YZ',origin=(50,0,0))
r=w0.sketch().circle(44).reset().face(w0.sketch().segment((-41,-6),(-3,-6)).segment((-3,-26)).segment((3,-26)).segment((3,-6)).segment((41,-6)).segment((41,6)).segment((3,6)).segment((3,26)).segment((-3,26)).segment((-3,6)).segment((-41,6)).close().assemble(),mode='s').finalize().extrude(-100)