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Feature-engine

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Feature-engine is a Python library with multiple transformers to engineer and select features for use in machine learning models. Feature-engine's transformers follow Scikit-learn's functionality with fit() and transform() methods to learn the transforming parameters from the data and then transform it.

Feature-engine features in the following resources

Blogs about Feature-engine

Documentation

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Current Feature-engine's transformers include functionality for:

  • Missing Data Imputation
  • Categorical Encoding
  • Discretisation
  • Outlier Capping or Removal
  • Variable Transformation
  • Variable Creation
  • Variable Selection
  • Datetime Features
  • Time Series
  • Preprocessing
  • Scaling
  • Scikit-learn Wrappers

Imputation Methods

  • MeanMedianImputer
  • ArbitraryNumberImputer
  • RandomSampleImputer
  • EndTailImputer
  • CategoricalImputer
  • AddMissingIndicator
  • DropMissingData

Encoding Methods

  • OneHotEncoder
  • OrdinalEncoder
  • CountFrequencyEncoder
  • MeanEncoder
  • WoEEncoder
  • RareLabelEncoder
  • DecisionTreeEncoder
  • StringSimilarityEncoder

Discretisation methods

  • EqualFrequencyDiscretiser
  • EqualWidthDiscretiser
  • GeometricWidthDiscretiser
  • DecisionTreeDiscretiser
  • ArbitraryDiscreriser

Outlier Handling methods

  • Winsorizer
  • ArbitraryOutlierCapper
  • OutlierTrimmer

Variable Transformation methods

  • LogTransformer
  • LogCpTransformer
  • ReciprocalTransformer
  • ArcsinTransformer
  • PowerTransformer
  • BoxCoxTransformer
  • YeoJohnsonTransformer

Variable Scaling methods

  • MeanNormalizationScaler

Variable Creation:

  • MathFeatures
  • RelativeFeatures
  • CyclicalFeatures
  • DecisionTreeFeatures()

Feature Selection:

  • DropFeatures
  • DropConstantFeatures
  • DropDuplicateFeatures
  • DropCorrelatedFeatures
  • SmartCorrelationSelection
  • ShuffleFeaturesSelector
  • SelectBySingleFeaturePerformance
  • SelectByTargetMeanPerformance
  • RecursiveFeatureElimination
  • RecursiveFeatureAddition
  • DropHighPSIFeatures
  • SelectByInformationValue
  • ProbeFeatureSelection
  • MRMR

Datetime

  • DatetimeFeatures
  • DatetimeSubtraction

Time Series

  • LagFeatures
  • WindowFeatures
  • ExpandingWindowFeatures

Pipelines

  • Pipeline
  • make_pipeline

Preprocessing

  • MatchCategories
  • MatchVariables

Wrappers:

  • SklearnTransformerWrapper

Installation

From PyPI using pip:

pip install feature_engine

From Anaconda:

conda install -c conda-forge feature_engine

Or simply clone it:

git clone https://github.com/feature-engine/feature_engine.git

Example Usage

>>> import pandas as pd
>>> from feature_engine.encoding import RareLabelEncoder

>>> data = {'var_A': ['A'] * 10 + ['B'] * 10 + ['C'] * 2 + ['D'] * 1}
>>> data = pd.DataFrame(data)
>>> data['var_A'].value_counts()
Out[1]:
A    10
B    10
C     2
D     1
Name: var_A, dtype: int64
>>> rare_encoder = RareLabelEncoder(tol=0.10, n_categories=3)
>>> data_encoded = rare_encoder.fit_transform(data)
>>> data_encoded['var_A'].value_counts()
Out[2]:
A       10
B       10
Rare     3
Name: var_A, dtype: int64

Find more examples in our Jupyter Notebook Gallery or in the documentation.

Contribute

Details about how to contribute can be found in the Contribute Page

Briefly:

  • Fork the repo
  • Clone your fork into your local computer:
git clone https://github.com/<YOURUSERNAME>/feature_engine.git
  • navigate into the repo folder
cd feature_engine
  • Install Feature-engine as a developer:
pip install -e .
  • Optional: Create and activate a virtual environment with any tool of choice
  • Install Feature-engine dependencies:
pip install -r requirements.txt

and

pip install -r test_requirements.txt
  • Create a feature branch with a meaningful name for your feature:
git checkout -b myfeaturebranch
  • Develop your feature, tests and documentation
  • Make sure the tests pass
  • Make a PR

Thank you!!

Documentation

Feature-engine documentation is built using Sphinx and is hosted on Read the Docs.

To build the documentation make sure you have the dependencies installed: from the root directory:

pip install -r docs/requirements.txt

Now you can build the docs using:

sphinx-build -b html docs build

License

The content of this repository is licensed under a BSD 3-Clause license.

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