tf.keras.backend.is_keras_tensor

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Returns whether x is a Keras tensor.

tf.keras.backend.is_keras_tensor(
    x
)

A "Keras tensor" is a tensor that was returned by a Keras layer, (Layer class) or by Input.

Arguments:

  • x: A candidate tensor.

Returns:

A boolean: Whether the argument is a Keras tensor.

Raises:

  • ValueError: In case x is not a symbolic tensor.

Examples:

np_var = np.array([1, 2]) 
# A numpy array is not a symbolic tensor. 
tf.keras.backend.is_keras_tensor(np_var) 
Traceback (most recent call last): 
 
ValueError: Unexpectedly found an instance of type `<class 'numpy.ndarray'>`. 
Expected a symbolic tensor instance. 
keras_var = tf.keras.backend.variable(np_var) 
# A variable created with the keras backend is not a Keras tensor. 
tf.keras.backend.is_keras_tensor(keras_var) 
False 
keras_placeholder = tf.keras.backend.placeholder(shape=(2, 4, 5)) 
# A placeholder is not a Keras tensor. 
tf.keras.backend.is_keras_tensor(keras_placeholder) 
False 
keras_input = tf.keras.layers.Input([10]) 
# An Input is a Keras tensor. 
tf.keras.backend.is_keras_tensor(keras_input) 
True 
keras_layer_output = tf.keras.layers.Dense(10)(keras_input) 
# Any Keras layer output is a Keras tensor. 
tf.keras.backend.is_keras_tensor(keras_layer_output) 
True