tf.keras.backend.placeholder

tf.keras.backend.placeholder(
    shape=None,
    ndim=None,
    dtype=None,
    sparse=False,
    name=None
)

Defined in tensorflow/python/keras/backend.py.

Instantiates a placeholder tensor and returns it.

Arguments:

  • shape: Shape of the placeholder (integer tuple, may include None entries).
  • ndim: Number of axes of the tensor. At least one of {shape, ndim} must be specified. If both are specified, shape is used.
  • dtype: Placeholder type.
  • sparse: Boolean, whether the placeholder should have a sparse type.
  • name: Optional name string for the placeholder.

Raises:

  • ValueError: If called with eager execution.

Returns:

Tensor instance (with Keras metadata included).

Examples: python >>> from keras import backend as K >>> input_ph = K.placeholder(shape=(2, 4, 5)) >>> input_ph <tf.Tensor 'Placeholder_4:0' shape=(2, 4, 5) dtype=float32>