tf.newaxis 和 numpy newaxis

n [71]: a1 = tf.constant([2,2], name="a1")

In [72]: a1
Out[72]: <tf.Tensor 'a1_5:0' shape=(2,) dtype=int32>

# add a new dimension
In [73]: a1_new = a1[tf.newaxis, :]

In [74]: a1_new
Out[74]: <tf.Tensor 'strided_slice_5:0' shape=(1, 2) dtype=int32>

# add one more dimension
In [75]: a1_new = a1[tf.newaxis, :, tf.newaxis]

In [76]: a1_new
Out[76]: <tf.Tensor 'strided_slice_6:0' shape=(1, 2, 1) dtype=int32>


>> x = np.arange(3)
>> x
array([0, 1, 2])
>> x.shape
(3,)

>> x[:, np.newaxis]
array([[0],
       [1],
       [2]])

>> x[:, None]
array([[0],
       [1],
       [2]])

>> x[:, np.newaxis].shape
 (3, 1)