title: Do I always have to keep a copy of training data if I do one hot encoding?
body: <p>I am doing one-hot-encoding for the categorical data. When I'm testing, I do something like this:</p>
  
  <pre><code>data.append(train_data_X)
  data.append(test_data_X)
  one_hot_encode(data)
  model.test(data[:test_data_X.shape[0])
  </code></pre>
  
  <p>I was wondering if there was a way of testing out my test data, without having access to my training data.</p>