title: Tensorflow: Inspecting Hash buckets for Categorical and Feature Columns
body: <p>I am fitting Linear Classifier for pretty wide and sparse data using number of <strong>Categorical Columns with hash bucket</strong> and <a href="https://www.tensorflow.org/api_docs/python/tf/feature_column/crossed_column" rel="nofollow noreferrer">Crossed Feature Columns</a> as Feature Columns.</p>
  
  <p>Later I want to use the weights/coefficients of the model in a custom serving infrastructure. I know how to extract the weights from the model, but obviously, for aforementioned columns, they come for an already hashed feature values.</p>
  
  <p>I can reconstruct a Hashtable (value -> hashed value) for a simple categorical columns using <strong>tf.string_to_hash_bucket_fast</strong>, but I am getting trouble doing that for Crossed Feature Columns.</p>
  
  <p>For a pair of values of two categorical columns building up a <strong>Crossed Column</strong> - how can I understand which bucket they will get into?</p>