Normalize (or project to sphere) selected vertices in Blender

normalize-verts-blender.py

import bmesh
def normalize_selected():
  m = bpy.context.active_object.data # get selected object's mesh
  bm = bmesh.new()   # create an empty BMesh
  bm.from_mesh(m)   # fill it in from a Mesh
  for v in bm.verts:
    if v.select:
      v.co.normalize()
  bm.to_mesh(m)
  
def project_selected(radius):
  m = bpy.context.active_object.data # get selected object's mesh
  bm = bmesh.new()   # create an empty BMesh
  bm.from_mesh(m)   # fill it in from a Mesh
  for v in bm.verts:
    if v.select:
      v.co.normalize()
      v.co = v.co * radius
  bm.to_mesh(m)