Category Encoders

A set of scikit-learn-style transformers for encoding categorical variables into numeric with different techniques. While ordinal, one-hot, and hashing encoders have similar equivalents in the existing scikit-learn version, the transformers in this library all share a few useful properties:

  • First-class support for pandas dataframes as an input (and optionally as output)

  • Can explicitly configure which columns in the data are encoded by name or index, or infer non-numeric columns regardless of input type

  • Can drop any columns with very low variance based on training set optionally

  • Portability: train a transformer on data, pickle it, reuse it later and get the same thing out.

  • Full compatibility with sklearn pipelines, input an array-like dataset like any other transformer

Usage

install as:

pip install category_encoders

or

conda install -c conda-forge category_encoders

To use:

import category_encoders as ce

encoder = ce.BackwardDifferenceEncoder(cols=[...])
encoder = ce.BaseNEncoder(cols=[...])
encoder = ce.BinaryEncoder(cols=[...])
encoder = ce.CatBoostEncoder(cols=[...])
encoder = ce.CountEncoder(cols=[...])
encoder = ce.GLMMEncoder(cols=[...])
encoder = ce.HashingEncoder(cols=[...])
encoder = ce.HelmertEncoder(cols=[...])
encoder = ce.JamesSteinEncoder(cols=[...])
encoder = ce.LeaveOneOutEncoder(cols=[...])
encoder = ce.MEstimateEncoder(cols=[...])
encoder = ce.OneHotEncoder(cols=[...])
encoder = ce.OrdinalEncoder(cols=[...])
encoder = ce.SumEncoder(cols=[...])
encoder = ce.PolynomialEncoder(cols=[...])
encoder = ce.TargetEncoder(cols=[...])
encoder = ce.WOEEncoder(cols=[...])
encoder = ce.QuantileEncoder(cols=[...])

encoder.fit(X, y)
X_cleaned = encoder.transform(X_dirty)

All of these are fully compatible sklearn transformers, so they can be used in pipelines or in your existing scripts. If the cols parameter isn’t passed, every non-numeric column will be converted. See below for detailed documentation

Contents:

Indices and tables