TensorFlow strings: what they are and how to work with them

Question

When I read file with tf.read_file I get something with type tf.string. Documentation says only that it is \"Variable length byte arrays. Each elem

Answer 1

Unlike Python, where a string can be treated as a list of characters for the purposes of slicing and such, TensorFlow's tf.strings are indivisible values. For instance, x below is a Tensor with shape (2,) whose each element is a variable length string.

x = tf.constant(["This is a string", "This is another string"])

However, to achieve what you want, TensorFlow provides the tf.decode_raw operator. It takes a tf.string tensor as input, but can decode the string into any other primitive data type. For instance, to interpret the string as a tensor of characters, you can do the following :

x = tf.constant("This is string")
x = tf.decode_raw(x, tf.uint8)
y = x[:4]
sess = tf.InteractiveSession()
print(y.eval())
# prints [ 84 104 105 115]