How to print the value of a Tensor object in TensorFlow?

Question

I have been using the introductory example of matrix multiplication in TensorFlow.

matrix1 = tf.constant([[3., 3.]])
matrix2 = tf.constant([[2.],[2.]])
produ         


        

Answer 1

In Tensorflow 2.0+ (or in Eager mode environment) you can call .numpy() method:

import tensorflow as tf

matrix1 = tf.constant([[3., 3.0]])
matrix2 = tf.constant([[2.0],[2.0]])
product = tf.matmul(matrix1, matrix2)

print(product.numpy()) 

Answer 2

You can use Keras, one-line answer will be to use eval method like so:

import keras.backend as K
print(K.eval(your_tensor))

Answer 3

Using tips provided in https://www.tensorflow.org/api_docs/python/tf/print I use the log_d function to print formatted strings.

import tensorflow as tf

def log_d(fmt, *args):
    op = tf.py_func(func=lambda fmt_, *args_: print(fmt%(*args_,)),
                    inp=[fmt]+[*args], Tout=[])
    return tf.control_dependencies([op])


# actual code starts now...

matrix1 = tf.constant([[3., 3.]])
matrix2 = tf.constant([[2.],[2.]])
product = tf.matmul(matrix1, matrix2)

with log_d('MAT1: %s, MAT2: %s', matrix1, matrix2): # this will print the log line
    product = tf.matmul(matrix1, matrix2)

with tf.Session() as sess:
    sess.run(product)