任何新版本的TF.Placeholder

Question

我使用tf.placeholder有问题，因为在新版本的Tensorflow 2.0中已将其删除。

我现在该怎么办才能使用此功能？

Answer 1

您只需直接将数据作为输入应用于层即可。例如：

import tensorflow as tf
import numpy as np
x_train = np.random.normal(size=(3, 2))
astensor = tf.convert_to_tensor(x_train)
logits = tf.keras.layers.Dense(2)(astensor)
print(logits.numpy())
# [[ 0.21247671  1.97068912]
#  [-0.17184766 -1.61471399]
#  [-0.03291694 -0.71419362]]

上面代码的TF1.x等效于：

import tensorflow as tf
import numpy as np
input_ = np.random.normal(size=(3, 2))
x = tf.placeholder(tf.float32, shape=(None, 2))
logits = tf.keras.layers.Dense(2)(x)
with tf.Session() as sess:
    sess.run(tf.global_variables_initializer())
    print(sess.run(logits, feed_dict={x:input_}))
# [[-0.17604277  1.8991518 ]
#  [-1.5802367  -0.7124136 ]
#  [-0.5170298   3.2034855 ]]