tf.compat.v1.placeholder

Inserts a placeholder for a tensor that will be always fed.

tf.compat.v1.placeholder(
    dtype, shape=None, name=None
)

Key Point: This tensor will produce an error if evaluated. Its value must be fed using the feed_dict optional argument to Session.run(), Tensor.eval(), or Operation.run().

For example:

x = tf.compat.v1.placeholder(tf.float32, shape=(1024, 1024))
y = tf.matmul(x, x)

with tf.compat.v1.Session() as sess:
  print(sess.run(y))  # ERROR: will fail because x was not fed.

  rand_array = np.random.rand(1024, 1024)
  print(sess.run(y, feed_dict={x: rand_array}))  # Will succeed.

Args
dtype	The type of elements in the tensor to be fed.
shape	The shape of the tensor to be fed (optional). If the shape is not specified, you can feed a tensor of any shape.
name	A name for the operation (optional).

Returns
A Tensor that may be used as a handle for feeding a value, but not evaluated directly.

Raises
RuntimeError	if eager execution is enabled

Eager Compatibility

Placeholders are not compatible with eager execution.