title: How to encode high cardinality feature?
body: <p>I have a dataset with more 1500+ category in single feature. how to encode these feature ? I tried with target encoding but there is category mismatch in training and test dataset. For example in training dataset there is A,B,C category of feature X while in test dataset there is A,B,D,F category of feature X ?</p>
  <p>How to deal with category mismatch and encode categorical variable with high cardinality?</p>