class_docstr: Utility transformer: Passes all specified columns through a given function.
class_docstr_tok: ["Utility","transformer",":","Passes","all","specified","columns","through","a","given","function","."]
docstr: Transforms the data.
code: def transform(self, data):
      """
      Transforms the data.
      """
  
      if not self._get("fitted"):
          raise RuntimeError(
              "`transform` called before `fit` or `fit_transform`."
          )
  
      data = data.copy()
      output_column_prefix = self._get("output_column_prefix")
  
      if output_column_prefix is None:
          prefix = ""
      else:
          prefix = output_column_prefix + "."
  
      transform_function = self._get("transform_function")
  
      feature_columns = self._get("features")
      feature_columns = _internal_utils.select_feature_subset(
          data, feature_columns
      )
  
      for f in feature_columns:
          data[prefix + f] = transform_function(data[f])
  
      return data
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from .None import TransformerBase
  from .None import TransformerChain
  from .None import TransformToFlatDictionary
  from turicreate.toolkits._model import PythonProxy
  from turicreate.toolkits._model import ExposeAttributesFromProxy
  from turicreate.toolkits._internal_utils import _toolkit_repr_print
  from turicreate.toolkits._internal_utils import _precomputed_field
  from turicreate.toolkits._internal_utils import _raise_error_if_not_sframe
  from turicreate.util import _raise_error_if_not_of_type
  from turicreate.toolkits._internal_utils import _check_categorical_option_type
  from .None import _internal_utils
  from array import array
  import textwrap
  from turicreate import SFrame
  import turicreate
label_desc: Use image node_id 9 for calling the _ColumnFunctionTransformation obj's underlying member method code with example usage: obj.transform(data) and returns: data