import cadquery as cq
w0=cq.Workplane('YZ',origin=(15,0,0))
r=w0.sketch().segment((-50,-23),(-44,-23)).segment((-44,-48)).segment((50,-48)).segment((50,23)).segment((23,23)).segment((23,48)).segment((-50,48)).close().assemble().reset().face(w0.sketch().segment((-23,23),(-2,23)).arc((-12,27),(-23,23)).assemble(),mode='s').finalize().extrude(-30)