As postalcodes could be mapped to geofenced or bucketized coordinate encoding you could try to take a look at:

  
      

      Medium – 18 May 20
  

  
    

Geographic coordinate encoding with TensorFlow feature columns 1

  Whenether you are facing latitudes and longitudes, make sure your machine learning model is doing the best.

  
    Reading time: 5 min read
  

  

  
    
    
  

  


P.s. for the feature column part in the mentioned tutorial it was related only to TF 1.x.

  
      

      TensorFlow
  

  
    

Migrating feature_columns to TF2's Keras Preprocessing Layers  | ...



  

  
    
    
  

  



  
      

      TensorFlow
  

  
    

Classify structured data using Keras preprocessing layers  | ...