Python tf.keras.backend.is_keras_tensor用法及代碼示例

返回 x 是否是 Keras 張量。

用法

tf.keras.backend.is_keras_tensor(
    x
)

"Keras tensor" 是由 Keras 層(Layer 類)或 Input 返回的張量。

例子：

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 a Keras tensor.
tf.keras.backend.is_keras_tensor(keras_placeholder)
True
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