In TensorFlow,what's the meaning of “:0” in a Variable's name?

Question

import tensorflow as tf
with tf.device(\'/gpu:0\'):
    foo = tf.Variable(1, name=\'foo\')
    assert foo.name == \"foo:0\"
with tf.device(\'/gpu:1\'):
    bar = tf.Vari         


        

Answer 1

It has to do with representation of tensors in underlying API. A tensor is a value associated with output of some op. In case of variables, there's a Variable op with one output. An op can have more than one output, so those tensors get referenced to as <op>:0, <op>:1 etc. For instance if you use tf.nn.top_k, there are two values created by this op, so you may see TopKV2:0 and TopKV2:1

a,b=tf.nn.top_k([1], 1)
print a.name # => 'TopKV2:0'
print b.name # => 'TopKV2:1'

How to understand the term `tensor` in TensorFlow?