# propcache > Accelerated property cache - **URL**: https://www.freshcrate.ai/projects/propcache - **Author**: Andrew Svetlov - **Category**: Frameworks - **Latest version**: `v0.5.2` (2026-05-08) - **License**: Apache-2.0 - **Source**: https://github.com/aio-libs/propcache/actions?query=branch:master - **Homepage**: https://github.com/aio-libs/propcache - **Language**: Python - **GitHub**: 33 stars, 18 forks - **Registry**: pypi (`propcache`) - **Tags**: `cext`, `cython`, `propcache`, `pypi` ## Description propcache ========= The module provides a fast implementation of cached properties for Python 3.9+. .. image:: https://github.com/aio-libs/propcache/actions/workflows/ci-cd.yml/badge.svg :target: https://github.com/aio-libs/propcache/actions?query=workflow%3ACI :align: right .. image:: https://codecov.io/gh/aio-libs/propcache/branch/master/graph/badge.svg :target: https://codecov.io/gh/aio-libs/propcache .. image:: https://badge.fury.io/py/propcache.svg :target: https://badge.fury.io/py/propcache .. image:: https://readthedocs.org/projects/propcache/badge/?version=latest :target: https://propcache.readthedocs.io .. image:: https://img.shields.io/pypi/pyversions/propcache.svg :target: https://pypi.python.org/pypi/propcache .. image:: https://img.shields.io/matrix/aio-libs:matrix.org?label=Discuss%20on%20Matrix%20at%20%23aio-libs%3Amatrix.org&logo=matrix&server_fqdn=matrix.org&style=flat :target: https://matrix.to/#/%23aio-libs:matrix.org :alt: Matrix Room — #aio-libs:matrix.org .. image:: https://img.shields.io/matrix/aio-libs-space:matrix.org?label=Discuss%20on%20Matrix%20at%20%23aio-libs-space%3Amatrix.org&logo=matrix&server_fqdn=matrix.org&style=flat :target: https://matrix.to/#/%23aio-libs-space:matrix.org :alt: Matrix Space — #aio-libs-space:matrix.org Introduction ------------ The API is designed to be nearly identical to the built-in ``functools.cached_property`` class, except for the additional ``under_cached_property`` class which uses ``self._cache`` instead of ``self.__dict__`` to store the cached values and prevents ``__set__`` from being called. For full documentation please read https://propcache.readthedocs.io. Installation ------------ :: $ pip install propcache The library is Python 3 only! PyPI contains binary wheels for Linux, Windows and MacOS. If you want to install ``propcache`` on another operating system where wheels are not provided, the the tarball will be used to compile the library from the source code. It requires a C compiler and and Python headers installed. To skip the compilation you must explicitly opt-in by using a PEP 517 configuration setting ``pure-python``, or setting the ``PROPCACHE_NO_EXTENSIONS`` environment variable to a non-empty value, e.g.: .. code-block:: console $ pip install propcache --config-settings=pure-python=false Please note that the pure-Python (uncompiled) version is much slower. However, PyPy always uses a pure-Python implementation, and, as such, it is unaffected by this variable. API documentation ------------------ The documentation is located at https://propcache.readthedocs.io. Source code ----------- The project is hosted on GitHub_ Please file an issue on the `bug tracker `_ if you have found a bug or have some suggestion in order to improve the library. Discussion list --------------- *aio-libs* google group: https://groups.google.com/forum/#!forum/aio-libs Feel free to post your questions and ideas here. Authors and License ------------------- The ``propcache`` package is derived from ``yarl`` which is written by Andrew Svetlov. It's *Apache 2* licensed and freely available. .. _GitHub: https://github.com/aio-libs/propcache ========= Changelog ========= .. You should *NOT* be adding new change log entries to this file, this file is managed by towncrier. You *may* edit previous change logs to fix problems like typo corrections or such. To add a new change log entry, please see https://pip.pypa.io/en/latest/development/#adding-a-news-entry we named the news folder "changes". WARNING: Don't drop the next directive! .. towncrier release notes start 0.4.1 ===== *(2025-10-08)* Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by `@Vizonex `__. *Related issues and pull requests on GitHub:* `#162 `__. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* `#155 `__. ---- 0.4.0 ===== *(2025-10-04)* Features -------- - Optimized propcache by replacing sentinel ``object`` for checking if the ``object`` is ``NULL`` and changed ``dict`` API for Python C-API -- by `@Vizonex `__. *Related issues and pull requests on GitHub:* `#121 `__. Contributor-facing changes -------------------------- - Builds have been added for arm64 Windows wheels and the ``reusable-build-wheel.yml`` workflow has been modified to allow for an OS value (``windows-11-arm``) which does not include the ``-latest`` postfix ## Recent releases | Version | Date | Urgency | Changes | | --- | --- | --- | --- | | `v0.5.2` | 2026-05-08 | High | 0.5.0 and 0.5.1 were tagged earlier today but never reached PyPI: 0.5.0's deploy failed at cibuildwheel's post-build pytest on free-threaded armv7l musllinux (SIGBUS under QEMU emulation while importing the C extension), and 0.5.1's deploy hit a transient sigstore Rekor 502 during the attestation step. 0.5.2 is the first of the three to actually publish. Features -------- - Added support for newer type hints and remove ``Optional`` and ``Union`` from all annotations -- by :user:`Vizonex` | | `0.4.1` | 2026-04-21 | Low | Imported from PyPI (0.4.1) | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | | `v0.4.1` | 2025-10-08 | Low | Bug fixes --------- - Fixed reference leak caused by ``Py_INCREF`` because Cython has its own reference counter systems -- by :user:`Vizonex`. *Related issues and pull requests on GitHub:* #162. Contributor-facing changes -------------------------- - Fixes the default value for the ``os`` parameter in ``reusable-build-wheel.yml`` to be ``ubuntu-latest`` instead of ``ubuntu``. *Related issues and pull requests on GitHub:* #155. ---- | ## Citation - HTML: https://www.freshcrate.ai/projects/propcache - Markdown: https://www.freshcrate.ai/projects/propcache.md - Dependencies JSON: https://www.freshcrate.ai/api/projects/propcache/deps _Generated by freshcrate.ai. Indexes pypi releases for AI-agent ecosystem packages._