title: Cannot get predictions of tensorflow DNNClassifier
body: <p>I'm using the code from the MNIST tutorial:</p>
  
  <pre><code>feature_columns = [tf.contrib.layers.real_valued_column("", dimension=4)]
  classifier = tf.contrib.learn.DNNClassifier(feature_columns=feature_columns,
                                              hidden_units=[10, 20, 10],
                                              n_classes=2,
                                              model_dir="/tmp/iris_model")
  
  classifier.fit(x=np.array(train, dtype = 'float32'),
                 y=np.array(y_tr, dtype = 'int64'),
                 steps=2000)
  
  accuracy_score = classifier.evaluate(x=np.array(test, dtype = 'float32'),
                                       y=y_test)["auc"]
  print('AUC: {0:f}'.format(accuracy_score))
  
  from tensorflow.contrib.learn import SKCompat
  ds_test_ar = np.array(ds_test, dtype = 'float32')
  
  ds_predict_tf = classifier.predict(input_fn = _my_predict_data)
  print('Predictions: {}'.format(str(ds_predict_tf)))
  </code></pre>
  
  <p>but at the end I got the following result instead of the predictions:</p>
  
  <pre><code>Predictions: &lt;generator object DNNClassifier.predict.&lt;locals&gt;.&lt;genexpr&gt; at 0x000002CE41101CA8&gt;
  </code></pre>
  
  <p>What did I do wrong?</p>