Level of detail demo - maya python pymel

lod1.py

import pymel.core.runtime as pm
import maya.cmds as cmds

lodList = list()
lodList = cmds.ls('lodGroup*')
if len(lodList) > 0:
    cmds.select('lodGroup1')
    pm.LevelOfDetailUngroup()
else:
    print('no group to ungroup')
sphereList = list()
sphereList = cmds.ls('pSphere*')
if len(sphereList) > 0:
    cmds.delete(sphereList)
else:
    print('no spheres to unsphere')


cmds.polySphere(r=1, sx=20, sy=20, ax=(0,1,0), cuv=2, ch=1)
cmds.polySphere(r=1, sx=7, sy=7, ax=(0,1,0), cuv=2, ch=1)
cmds.polySphere(r=1, sx=5, sy=5, ax=(0,1,0), cuv=2, ch=1)
cmds.polySphere(r=1, sx=3, sy=3, ax=(0,1,0), cuv=2, ch=1)
cmds.select('pSphere1', 'pSphere2', 'pSphere3', 'pSphere4',r=True)

pm.LevelOfDetailGroup()

for i in range (0, 3):
    myThr = (i+1)*10
    st = 'lodGroup1.threshold[%i]' %(i)    
    cmds.setAttr(st, myThr)