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pybaum

PyPI PyPI - Python Version PyPI - License https://readthedocs.org/projects/pybaum/badge/?version=latest https://img.shields.io/github/actions/workflow/status/OpenSourceEconomics/pybaum/main.yml?branch=main pre-commit.ci status

Installation

pybaum is available on PyPI and Anaconda.org. Install it with

$ pip install pybaum

# or

$ conda install -c conda-forge pybaum

About

pybaum provides tools to work with pytrees which is a concept borrowed from JAX.

What is a pytree?

In pybaum, we use the term pytree to refer to a tree-like structure built out of container-like Python objects. Classes are considered container-like if they are in the pytree registry, which by default includes lists, tuples, and dicts. That is:

  1. Any object whose type is not in the pytree container registry is considered a leaf pytree.
  2. Any object whose type is in the pytree container registry, and which contains pytrees, is considered a pytree.

For each entry in the pytree container registry, a container-like type is registered with a pair of functions that specify how to convert an instance of the container type to a (children, metadata) pair and how to convert such a pair back to an instance of the container type. Using these functions, pybaum can canonicalize any tree of registered container objects into tuples.

Example pytrees:

[1, "a", object()]  # 3 leaves

(1, (2, 3), ())  # 3 leaves

[1, {"k1": 2, "k2": (3, 4)}, 5]  # 5 leaves

pybaum can be extended to consider other container types as pytrees.