tf.keras.backend.placeholder

TensorFlow 2 version View source on GitHub

Instantiates a placeholder tensor and returns it.

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.
ragged Boolean, whether the placeholder should have a ragged type. In this case, values of 'None' in the 'shape' argument represent ragged dimensions. For more information about RaggedTensors, see this guide.

ValueError If called with eager execution
ValueError If called with sparse = True and ragged = True.

Tensor instance (with Keras metadata included).

Examples:

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>