cachetools ======================================================================== This module provides various memoizing collections and decorators, including variants of the Python 3 Standard Library `@lru_cache`_ function decorator. .. code-block:: python from cachetools import cached, LRUCache, TTLCache # speed up calculating Fibonacci numbers with dynamic programming @cached(cache={}) def fib(n): return n if n < 2 else fib(n - 1) + fib(n - 2) # cache least recently used Python Enhancement Proposals @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() # cache weather data for no longer than ten minutes @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`_. In general, a cache's size is the total size of its items, and an item's size is a property or function of its value, e.g. the result of ``sys.getsizeof(value)``. For the trivial but common case that each item counts as ``1``, a cache's size is equal to the number of its items, or ``len(cache)``. Multiple cache classes based on different caching algorithms are implemented, and decorators for easily memoizing function and method calls are provided, too. For more information, please refer to the online documentation_. Installation ------------------------------------------------------------------------ Install cachetools using pip:: pip install cachetools Project Resources ------------------------------------------------------------------------ .. image:: http://img.shields.io/pypi/v/cachetools.svg?style=flat :target: https://pypi.python.org/pypi/cachetools/ :alt: Latest PyPI version .. image:: http://img.shields.io/travis/tkem/cachetools/master.svg?style=flat :target: https://travis-ci.org/tkem/cachetools/ :alt: Travis CI build status .. image:: http://img.shields.io/coveralls/tkem/cachetools/master.svg?style=flat :target: https://coveralls.io/r/tkem/cachetools :alt: Test coverage .. image:: https://readthedocs.org/projects/cachetools/badge/?version=latest&style=flat :target: http://cachetools.readthedocs.io/en/latest/ :alt: Documentation Status - `Issue Tracker`_ - `Source Code`_ - `Change Log`_ License ------------------------------------------------------------------------ Copyright (c) 2014-2019 Thomas Kemmer. Licensed under the `MIT License`_. .. _@lru_cache: http://docs.python.org/3/library/functools.html#functools.lru_cache .. _mutable: http://docs.python.org/dev/glossary.html#term-mutable .. _mapping: http://docs.python.org/dev/glossary.html#term-mapping .. _cache algorithm: http://en.wikipedia.org/wiki/Cache_algorithms .. _Documentation: http://cachetools.readthedocs.io/en/latest/ .. _Issue Tracker: https://github.com/tkem/cachetools/issues/ .. _Source Code: https://github.com/tkem/cachetools/ .. _Change Log: https://github.com/tkem/cachetools/blob/master/CHANGES.rst .. _MIT License: http://raw.github.com/tkem/cachetools/master/LICENSE