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This module provides various memoizing collections and decorators, including variants of the Python Standard Library's @lru_cache_ function decorator.

.. code-block:: python

from cachetools import cached, LRUCache, TTLCache

@cached(cache={}) def fib(n): return n if n < 2 else fib(n - 1) + fib(n - 2)

@cached(cache=LRUCache(maxsize=32)) def get_pep(num): url = 'http://www.python.org/dev/peps/pep-%04d/' % num with urllib.request.urlopen(url) as s: return s.read()

@cached(cache=TTLCache(maxsize=1024, ttl=600)) def get_weather(place): return owm.weather_at_place(place).get_weather()

For the purpose of this module, a cache is a mutable_ mapping_ of a fixed maximum size. When the cache is full, i.e. by adding another item the cache would exceed its maximum size, the cache must choose which item(s) to discard based on a suitable cache algorithm_.

This module provides multiple cache classes based on different cache algorithms, as well as decorators for easily memoizing function and method calls.

cachetools is available from PyPI_ and can be installed by running::

pip install cachetools

Typing stubs for this package are provided by typeshed_ and can be installed by running::

pip install types-cachetools

• Documentation_
• Issue tracker_
• Source code_
• Change log_

• asyncache_: Helpers to use cachetools_ with asyncio.
• cachetools-async_: Helpers to use cachetools_ with asyncio.
• cacheing_: Pure Python Cacheing Library.
• CacheToolsUtils_: Stackable cache classes for sharing, encryption, statistics and more on top of cachetools_, redis_ and memcached_.
• shelved-cache_: Persistent cache implementation for Python cachetools_.

Copyright (c) 2014-2026 Thomas Kemmer.

Licensed under the MIT License_.

.. _@lru_cache: https://docs.python.org/3/library/functools.html#functools.lru_cache .. _mutable: https://docs.python.org/dev/glossary.html#term-mutable .. _mapping: https://docs.python.org/dev/glossary.html#term-mapping .. _cache algorithm: https://en.wikipedia.org/wiki/Cache_algorithms

.. _PyPI: https://pypi.org/project/cachetools/ .. _typeshed: https://github.com/python/typeshed/ .. _Documentation: https://cachetools.readthedocs.io/ .. _Issue tracker: https://github.com/tkem/cachetools/issues/ .. _Source code: https://github.com/tkem/cachetools/ .. _Change log: https://github.com/tkem/cachetools/blob/master/CHANGELOG.rst .. _MIT License: https://raw.github.com/tkem/cachetools/master/LICENSE

.. _asyncache: https://pypi.org/project/asyncache/ .. _cachetools-async: https://pypi.org/project/cachetools-async/ .. _cacheing: https://pypi.org/project/cacheing/ .. _CacheToolsUtils: https://pypi.org/project/CacheToolsUtils/ .. _shelved-cache: https://pypi.org/project/shelved-cache/ .. _cachetools: https://pypi.org/project/cachetools/ .. _redis: https://redis.io/ .. _memcached: https://memcached.org/