shapr: Explaining Machine Learning Models with Conditional Shapley Values in R and Python

This paper introduces the shapr package, a versatile tool for generating Shapley value explanations for machine learning and statistical regression models in both R and Python. The package emphasizes conditional Shapley value estimates, providing a comprehensive range of approaches for accurately capturing feature dependencies, which is crucial for correct model interpretation and lacking in similar software. In addition to regular tabular data, the shapr R-package includes specialized functionality for explaining time series forecasts. The package offers a minimal set of user functions with sensible defaults for most use cases while providing extensive flexibility for advanced users to fine-tune computations. Additional features include parallelized computations, iterative estimation with convergence detection, and rich visualization tools. shapr also extends its functionality to compute causal and asymmetric Shapley values when causal information is available. In addition, we introduce the shaprpy Python library, which brings core capabilities of shapr to the Python ecosystem. Overall, the package aims to enhance the interpretability of predictive models within a powerful and user-friendly framework.