old_contents: # -*- coding: utf-8 -*- 
  from rest_framework import serializers
  from models import Operacion
  
  class OperacionSerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
          model = Operacion
          fields = ('url', 'op1', 'op2', 'operacion','resultado',)
  
new_contents: # -*- coding: utf-8 -*- 
  from rest_framework import serializers
  from models import Operacion
  
  class OperacionSerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
          model = Operacion
          fields = ('url', 'op1', 'op2', 'operacion','resultado',)
          read_only_fields = ('resultado',) 
  
subject: Convierte el el campo resultado a solo lectura