# Copyright 2022 The SQLNet Company GmbH
#
# This file is licensed under the Elastic License 2.0 (ELv2).
# Refer to the LICENSE.txt file in the root of the repository
# for details.
#
"""
Contains routines for preprocessing data frames.
"""
from dataclasses import dataclass
from .preprocessor import _Preprocessor
from .validate import _validate
# NOTE: The r at the beginning of the docstring
# is necessary to correctly display the characters.
# https://docutils.sourceforge.io/docs/ref/rst/directives.html#code
[docs]@dataclass(repr=False)
class TextFieldSplitter(_Preprocessor):
r"""
A TextFieldSplitter splits columns with role :const:`getml.data.roles.text`
into relational bag-of-words representations to allow the
feature learners to learn patterns based on
the prescence of certain words within the text fields.
Text fields will be splitted on a whitespace or any of the
following characters:
.. code:: python
; , . ! ? - | " \t \v \f \r \n % ' ( ) [ ] { }
Refer to the :ref:`User guide <text_fields>` for more information.
Example:
.. code-block:: python
text_field_splitter = getml.preprocessors.TextFieldSplitter()
pipe = getml.Pipeline(
population=population_placeholder,
peripheral=[order_placeholder, trans_placeholder],
preprocessors=[text_field_splitter],
feature_learners=[feature_learner_1, feature_learner_2],
feature_selectors=feature_selector,
predictors=predictor,
share_selected_features=0.5
)
"""
[docs] def validate(self, params=None):
"""Checks both the types and the values of all instance
variables and raises an exception if something is off.
Args:
params (dict, optional):
A dictionary containing
the parameters to validate. If not is passed,
the own parameters will be validated.
"""
_validate(self, params)