toolz

List processing tools and functional utilities

toolz Permissive license BSD-3-Clause AGING ★ 5,151 v1.1.0 released 2025-10-17

Install

toolz on PyPI

pip

pip install toolz

uv

uv add toolz

poetry

poetry add toolz

Package facts

License	BSD-3-Clause (permissive)
Python support	supports the current Python release (>=3.9)
Install friction	low — pure-Python wheel
Runtime dependencies	none
Maintenance	aging — 300 days since the last release
Last repo commit	2026-01-01
First released	2013-09-11
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: toolz-1.1.0-py3-none-any.whl

Keywords: functional, utility, itertools, functools

Development Status :: 5 - Production/StableProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPy

About toolz

from the package's own PyPI description — quoted content, verbatim

Toolz

A set of utility functions for iterators, functions, and dictionaries.

See the PyToolz documentation at https://toolz.readthedocs.io

LICENSE

New BSD. See License File <https://github.com/pytoolz/toolz/blob/master/LICENSE.txt>__.

Install

toolz is on the Python Package Index (PyPI):

pip install toolz

Structure and Heritage

toolz is implemented in three parts:

|literal itertoolz|_, for operations on iterables. Examples: groupby, unique, interpose,

|literal functoolz|_, for higher-order functions. Examples: memoize, curry, compose,

|literal dicttoolz|_, for operations on dictionaries. Examples: assoc, update-in, merge.

.. |literal itertoolz| replace:: itertoolz .. _literal itertoolz: https://github.com/pytoolz/toolz/blob/master/toolz/itertoolz.py

.. |literal functoolz| replace:: functoolz .. _literal functoolz: https://github.com/pytoolz/toolz/blob/master/toolz/functoolz.py

.. |literal dicttoolz| replace:: dicttoolz .. _literal dicttoolz:...

Read as markdown · JSON record · Source repository · Docs

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

Toolz provides a set of utility functions for functional programming with iterators, functions, and dictionaries—composable tools for list processing and higher-order operations.

Toolz has zero runtime dependencies and installs as a pure-Python wheel with low friction. The project is aging (300 days since last release) but remains actively maintained for critical fixes and security issues; it is highly depended upon and stable.

Toolz is licensed under BSD-3-Clause (permissive), allowing commercial and private use with minimal restrictions—only requiring license and copyright notice retention.

Usage

pip install toolz

from toolz import compose, frequencies
from toolz.curried import map

wordcount = compose(frequencies, map(str.lower), str.split)
result = wordcount("hello world hello")
print(result)  # {'hello': 2, 'world': 1}

Requires Python 3.9 or later.

Verdict: Toolz is a mature, dependency-free utility library for functional programming in Python. With no known vulnerabilities, permissive licensing, and broad adoption (top 1000 PyPI), it is a safe and lightweight choice for functional composition tasks. The aging maintenance status reflects intentional stability rather than abandonment—the maintainers commit to critical fixes and security patches.

Needs verification

Whether the project accepts community contributions beyond critical bug fixes and security patches
Performance characteristics compared to standard library itertools and functools for typical use cases

functional programming utilities pythoniterator tools groupby uniquefunction composition memoize currydictionary operations merge assocfunctional list processingitertools functools utilitiescompose chain functions