Development Status
- 5 - Production/Stable
Intended Audience
- Developers
License
- OSI Approved :: Apache Software License
Programming Language
- Cython
- Python
- Python :: 3
- Python :: 3.9
- Python :: 3.10
- Python :: 3.11
- Python :: 3.12
- Python :: 3.13
- Python :: 3.14
Topic
- Internet :: WWW/HTTP
- Software Development :: Libraries :: Python Modules
propcache
The module provides a fast implementation of cached properties for Python 3.9+.
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.:
$ pip install propcache --config-settings=pure-python=falsePlease 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.
0.4.1
(2025-10-08)
Bug fixes
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
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 – by @finnagin.
Related issues and pull requests on GitHub: #133.
Added CI for CPython 3.14 – by @kumaraditya303.
Related issues and pull requests on GitHub: #140.
0.3.2
(2025-06-09)
Improved documentation
Packaging updates and notes for downstreams
Updated to use Cython 3.1 universally across the build path – by @lysnikolaou.
Related issues and pull requests on GitHub: #117.
Made Cython line tracing opt-in via the with-cython-tracing build config setting – by @bdraco.
Previously, line tracing was enabled by default in pyproject.toml, which caused build issues for some users and made wheels nearly twice as slow.
Now line tracing is only enabled when explicitly requested via pip install . --config-setting=with-cython-tracing=true or by setting the PROPCACHE_CYTHON_TRACING environment variable.
Related issues and pull requests on GitHub: #118.
0.3.1
(2025-03-25)
Bug fixes
Improved typing annotations, fixing some type errors under correct usage and improving typing robustness generally – by @Dreamsorcerer.
Related issues and pull requests on GitHub: #103.
0.3.0
(2025-02-20)
Features
Implemented support for the free-threaded build of CPython 3.13 – by @lysnikolaou.
Related issues and pull requests on GitHub: #84.
Packaging updates and notes for downstreams
Started building wheels for the free-threaded build of CPython 3.13 – by @lysnikolaou.
Related issues and pull requests on GitHub: #84.
Contributor-facing changes
GitHub Actions CI/CD is now configured to manage caching pip-ecosystem dependencies using re-actors/cache-python-deps – an action by @webknjaz that takes into account ABI stability and the exact version of Python runtime.
Related issues and pull requests on GitHub: #93.
0.2.1
(2024-12-01)
Bug fixes
Stopped implicitly allowing the use of Cython pre-release versions when building the distribution package – by @ajsanchezsanz and @markgreene74.
Related commits on GitHub: 64df0a6.
Fixed wrapped and func not being accessible in the Cython versions of propcache.api.cached_property and propcache.api.under_cached_property decorators – by @bdraco.
Related issues and pull requests on GitHub: #72.
Removals and backward incompatible breaking changes
Packaging updates and notes for downstreams
Stopped implicitly allowing the use of Cython pre-release versions when building the distribution package – by @ajsanchezsanz and @markgreene74.
Related commits on GitHub: 64df0a6.
0.2.0
(2024-10-07)
Bug fixes
Features
Improved documentation
Packaging updates and notes for downstreams
0.1.0
(2024-10-03)
Features
0.0.0
(2024-10-02)
Initial release.