import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,-3))
r=w0.sketch().segment((-50,-29),(23,-29)).segment((23,-36)).segment((50,-36)).segment((45,36)).segment((23,36)).segment((23,25)).segment((-50,25)).close().assemble().push([(0,-4)]).circle(22,mode='s').finalize().extrude(6)