tensorflow/models · error · TypeError

optimizer is not an object of tf_keras.optimizers.Optimizer

Error message

optimizer is not an object of tf_keras.optimizers.Optimizer

What it means

Error "optimizer is not an object of tf_keras.optimizers.Optimizer" thrown in tensorflow/models.

Source

Thrown at official/legacy/image_classification/optimizer_factory.py:88

      slow_step_size: A floating point value. The ratio for updating the slow
        weights.
      name: Optional name for the operations created when applying gradients.
        Defaults to "Lookahead".
      **kwargs: keyword arguments. Allowed to be {`clipnorm`, `clipvalue`, `lr`,
        `decay`}. `clipnorm` is clip gradients by norm; `clipvalue` is clip
        gradients by value, `decay` is included for backward compatibility to
        allow time inverse decay of learning rate. `lr` is included for backward
        compatibility, recommended to use `learning_rate` instead.
    """
    super().__init__(name, **kwargs)

    if isinstance(optimizer, str):
      optimizer = tf_keras.optimizers.get(optimizer)
    if not isinstance(
        optimizer,
        (tf_keras.optimizers.Optimizer, tf_keras.optimizers.legacy.Optimizer),
    ):
      raise TypeError(
          'optimizer is not an object of tf_keras.optimizers.Optimizer'
      )

    self._optimizer = optimizer
    self._set_hyper('sync_period', sync_period)
    self._set_hyper('slow_step_size', slow_step_size)
    self._initialized = False
    self._track_trackable(self._optimizer, 'lh_base_optimizer')

  def _create_slots(self, var_list):
    self._optimizer._create_slots(var_list=var_list)  # pylint: disable=protected-access
    for var in var_list:
      self.add_slot(var, 'slow', initializer=var)

  def _create_hypers(self):
    self._optimizer._create_hypers()  # pylint: disable=protected-access

  def _prepare(self, var_list):

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/legacy/image_classification/optimizer_factory.py:88 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tensorflow/models@e006f5f0d5 (2026-08-24). Data as JSON: /api/errors/ebde3d4cf13fa1dc. Report an issue: GitHub.