class_docstr: Encode the categorical features to numerical features.
class_docstr_tok: ["Encode","the","categorical","features","to","numerical","features","."]
code: def __init__(self, **kwargs):
      super().__init__(**kwargs)
      self.column_types = None
      self.column_names = None
  
imports: from typing import Optional
  from typing import Tuple
  from typing import Union
  from keras_tuner.engine import hyperparameters
  from tensorflow import nest
  from tensorflow.keras import layers
  from autokeras import analysers
  from autokeras import keras_layers
  from autokeras.engine import block
  from autokeras.utils import io_utils
  from autokeras.utils import utils
label_desc: Use image node_id 1 to create a new CategoricalToNumerical object from inherited base classes: block_module with example: obj = CategoricalToNumerical()