code: def handle(self, locale, app=None, **options):
          
          translation.activate(settings.LANGUAGE_CODE)
          if app:
              unpack = app.split('.')
  
              if len(unpack) == 2:
                  models = [get_model(unpack[0], unpack[1])]
              elif len(unpack) == 1:
                  models = get_models(get_app(unpack[0]))
          else:
              models = get_models()
              
          for model in models:
              if hasattr(model, 'localized_fields'):
                  i18n.unregister(model)
                  model_full_name = '%s.%s' % (model._meta.app_label, model._meta.module_name)
                  update_instances = set()
                  messages = []
                  
                  for instance in model.objects.all():
                      for field in model.localized_fields:
                          local_field_name = get_real_fieldname(field, locale)
                          
                          if  hasattr(instance, local_field_name):
                                  local_field_value = getattr(instance, local_field_name)
                                  if local_field_value not in (None, u''):
                                      setattr(instance, local_field_name, None)
                                  
                                      update_instances.add(instance)
                                      messages.append(u"%s %s %s : %s will become reset to None" % (model_full_name, instance, local_field_name, force_unicode(local_field_value)))
  
                  if len(update_instances):
                      if self.ask_for_confirmation(messages, u'%s.%s' % (model._meta.app_label, model._meta.module_name)):
                          for update_instance in update_instances:
                              print u"resetting %s" % update_instance
                              update_instance.save()
docs: command execution