title: How to index a list with a TensorFlow tensor?
body: <p>Assume a list with non concatenable objects which needs to be accessed via a look up table. So the list index will be a tensor object but this is not possible.</p>
  
  <pre><code> tf_look_up = tf.constant(np.array([3, 2, 1, 0, 4]))
   index = tf.constant(2)
   list = [0,1,2,3,4]
  
   target = list[tf_look_up[index]]
  </code></pre>
  
  <p>This will bring out the following error message. </p>
  
  <pre><code> TypeError: list indices must be integers or slices, not Tensor
  </code></pre>
  
  <p>Is the a way/workaround to index lists with tensors?</p>