title: Tensorflow 'features' format
body: <p>I'm a total begginer with AI and tensorflow, so please forgive if this is a dumb question.
  I've trained a tensorflow network using a script based on this tutorial:</p>
  
  <p><a href="https://www.tensorflow.org/versions/r0.10/tutorials/wide_and_deep/index.html" rel="nofollow">https://www.tensorflow.org/versions/r0.10/tutorials/wide_and_deep/index.html</a></p>
  
  <p>I believe training was ok.
  Now I whant to run this method to make a prediction for a single input:</p>
  
  <pre><code>tf.contrib.learn.DNNClassifier.predict_proba(x=x)
  </code></pre>
  
  <p>But I cannot find any documentation on how to build the "x" parameter...
  I tryed: </p>
  
  <pre><code> x = {k: tf.SparseTensor(indices=[[0, 0]], values=[d_data[k]], shape=[1, 1]) for k in COLUMNS}
  </code></pre>
  
  <p>Where:
  <strong>d_data</strong> is a dictionary containing about 150 key/value pairs.
  <strong>COLUMNS</strong> is a list with all the keys needed. 
  This same setup was used to train the network.</p>
  
  <p>But got the error:  </p>
  
  <pre><code>AttributeError: 'dict' object has no attribute 'dtype'
  </code></pre>
  
  <p>So... x should not be a 'dict'... but what should it be then?
  Can anyone give me some directions?</p>
  
  <p>Thanks a lot.</p>