title: Tensorflow AttributeError: 'NoneType' object has no attribute 'keys'
body: <p>I am trying to make a simple Image Classifier using Tensorflow. 
  From here
  <a href="https://medium.com/@linjunghsuan/create-a-simple-image-classifier-using-tensorflow-a7061635984a" rel="nofollow noreferrer">https://medium.com/@linjunghsuan/create-a-simple-image-classifier-using-tensorflow-a7061635984a</a></p>
  
  <p>I am using Anaconda2 on Windows 10 (64bit)
  Packages used 
  The following NEW packages will be INSTALLED:</p>
  
  <pre><code>certifi:        2016.2.28-py35_0
  pip:            9.0.3-py35_1
  python:         3.5.4-0
  setuptools:     36.4.0-py35_1
  vc:             14-0
  vs2015_runtime: 14.0.25420-0
  wheel:          0.29.0-py35_0
  wincertstore:   0.2-py35_0
  </code></pre>
  
  <p>I downloaded retrain.py from 
  <a href="https://github.com/tensorflow/tensorflow/blob/master/tensorflow/examples/image_retraining/retrain.py" rel="nofollow noreferrer">https://github.com/tensorflow/tensorflow/blob/master/tensorflow/examples/image_retraining/retrain.py</a></p>
  
  <p>When I am trying to train the data using </p>
  
  <pre><code>python {$your-working_directory}/retrain.py
  </code></pre>
  
  <p>I am getting these errors </p>
  
  <pre><code>[tensorflow] C:\Users\user&gt;python F:\Tensorflow\retrain.py
  ERROR:tensorflow:Image directory '' not found.
  Traceback (most recent call last):
    File "F:\Tensorflow\retrain.py", line 1409, in &lt;module&gt;
      tf.app.run(main=main, argv=[sys.argv[0]] + unparsed)
    File "F:\Coursera ML\Anaconda2\envs\tensorflow\lib\site-packages\tensorflow\python\platform\app.py", line 126, in run
      _sys.exit(main(argv))
    File "F:\Tensorflow\retrain.py", line 1061, in main
      class_count = len(image_lists.keys())
  AttributeError: 'NoneType' object has no attribute 'keys'
  </code></pre>
  
  <p>In F:\Tensorflow there is one folder with the dataset images and the retrain.py</p>
  
  <p>I am a beginner and this is my first time using Tensorflow and Deep Learning. 
  I scrubbed through StackOverflow and Github but I couldnt find any solution that worked. 
  I think i am making an error with the directories of the images of the data set. 
  Any help is appreciated. 
  Thanks in advance.
  (Also if you need additional information regarding anything please do let me know)</p>