How to define set-node from circle in Python script

I want to define set-node to circles in a Python script for abaqus.

This code is for Geometry mode. What should be done to define a category node? And select nodes around the circle?

facemat=mdb.models['Model-1'].rootAssembly.instances['matrix-1'].edges.findAt((x+r,y,0),)
m = facemat.index

mdb.models['Model-1'].rootAssembly.Set(name='Set-%d'%(j+1), edges=
   mdb.models['Model-1'].rootAssembly.instances['matrix-1'].edges[m:m+1])

Image of the model