How to request energy field output in ABAQUS Python

I m trying to extract energy at each integration point in Abaqus. I can do it for stresses or strains but i cant do for the energetical quantities. The obtained error is : “KeyError: 'ELEN'”, but in Abaqus it is the good keyword… Below it is my code to extract it :

from odbAccess import*import numpy as np

odb = openOdb(path='C:/Desktop/Fish1.odb')# lastFrame = odb.steps['Step-2'].frames[-1]
lastFrame = odb.steps['Step-1'].frames[-1]

topCenter = \
odb.rootAssembly.instances['PART-1-1']
stressField = lastFrame.fieldOutputs['ELEN']

field = stressField.getSubset(region=topCenter,
position=INTEGRATION_POINT, elementType ='CPS3')
fieldValues = field.values

sortie = open('C:/Users/tests.txt','w')
sortie.write('Eleme \t Integ \t\t PE11 \t\t\t PE22 \t\t\t PE12 \n')for v in fieldValues:
sortie.write('%-10.2f'%( v.elementLabel))if v.integrationPoint:
sortie.write('%-10.2f'%(v.integrationPoint))
sortie.write('%-10.3f\t\t %-10.3f\t\t %-10.3f\t\t %-10.3f\t\t \n'%(v.data[0], v.data[1], v.data[2], v.data[3]))

sortie.close()