serializer.py

def validate(self, attrs):
   
    whatsapp = attrs.get('whatsapp', self.object.whatsapp)
    whatsapp_h = attrs.get('whatsapp_h', self.object.whatsapp_h)
    prontuario = attrs.get("prontuario", self.object.prontuario
                           
    try:
                           
        obj = tb_Paciente.objects.filter(whatsapp=whatsapp, whatsapp_h=whatsapp_h, prontuario=prontuario).exists
                           ()
    except tb_Paciente.DoesNotExist:
        return attrs
    if self.object and obj.id == self.object.id:
        return attrs
    else:
        raise serializers.ValidationError('Este dado já existe na nossa base')