feature-engine 0.3.1

Feature engineering package that follows sklearn functionality

Feature Engine

Feature-engine is a Python library that contains several transformers to engineer features for use in machine learning models. Feature-engine's transformers follow Scikit-learn like functionality with fit() and transform() methods to first learn the transforming paramenters from data and then transform the data. Current Feature-engine's transformers include functionality for:

• Missing data imputation
• Categorical variable encoding
• Outlier removal
• Discretisation
• Numerical Variable Transformation

Important Links

• Documentation: http://feature-engine.readthedocs.io
• Home page: https://www.trainindata.com/feature-engine

Imputing Methods

• MeanMedianImputer
• RandomSampleImputer
• EndTailImputer
• AddNaNBinaryImputer
• CategoricalVariableImputer
• FrequentCategoryImputer
• ArbitraryNumberImputer

Encoding Methods

• CountFrequencyCategoricalEncoder
• OrdinalCategoricalEncoder
• MeanCategoricalEncoder
• WoERatioCategoricalEncoder
• OneHotCategoricalEncoder
• RareLabelCategoricalEncoder

Outlier Handling methods

• Winsorizer
• ArbitraryOutlierCapper

Discretisation methods

• EqualFrequencyDiscretiser
• EqualWidthDiscretiser
• DecisionTreeDiscretiser

Variable Transformation methods

• LogTransformer
• ReciprocalTransformer
• PowerTransformer
• BoxCoxTransformer
• YeoJohnsonTransformer

Installing

pip install feature_engine

or

git clone https://github.com/solegalli/feature_engine.git

Usage

from feature_engine.categorical_encoders import RareLabelEncoder

rare_encoder = RareLabelEncoder(tol = 0.05, n_categories=5)
rare_encoder.fit(data, variables = ['Cabin', 'Age'])
data_encoded = rare_encoder.transform(data)

See more usage examples in the jupyter notebooks in the example folder of this repository, or in the documentation: http://feature-engine.readthedocs.io

License

BSD 3-Clause

Authors

• Soledad Galli - Initial work - Feature Engineering Online Course.

References

Many of the engineering and encoding functionality is inspired by this series of articles from the 2009 KDD competition.

To learn more about the rationale, functionality, pros and cos of each imputer, encoder and transformer, refer to the Feature Engineering Online Course

For a summary of the methods check this presentation and this article

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