title: Tensorflow One Hot Encoder?
body: <p>Does tensorflow have something similar to scikit learn's <a href="http://scikit-learn.org/stable/modules/generated/sklearn.preprocessing.OneHotEncoder.html">one hot encoder</a> for processing categorical data?  Would using a placeholder of tf.string behave as categorical data?</p>
  
  <p>I realize I can manually pre-process the data before sending it to tensorflow, but having it built in is very convenient.</p>