title: Issue feeding a list into feed_dict in TensorFlow
body: <p>I'm trying to pass a list into <code>feed_dict</code>, however I'm having trouble doing so. Say I have:</p>
  
  <pre><code>inputs = 10 * [tf.placeholder(tf.float32, shape=(batch_size, input_size))]
  </code></pre>
  
  <p>where inputs is fed into some function <code>outputs</code> that I want to compute. So to run this in tensorflow, I created a session and ran the following:</p>
  
  <pre><code>sess.run(outputs, feed_dict = {inputs: data}) 
  #data is my list of inputs, which is also of length 10
  </code></pre>
  
  <p>but I get an error, <code>TypeError: unhashable type: 'list'.</code>
  However, I'm able to pass the data element-wise like so:</p>
  
  <pre><code>sess.run(outputs, feed_dict = {inputs[0]: data[0], ..., inputs[9]: data[9]}) 
  </code></pre>
  
  <p>So I'm wondering if there's a way I can solve this issue. I've also tried to construct a dictionary(using a <code>for</code> loop), however this results in a dictionary with a single element, where they key is: 
  <code>tensorflow.python.framework.ops.Tensor at 0x107594a10</code></p>