98 lines
3.3 KiB
ReStructuredText
98 lines
3.3 KiB
ReStructuredText
|
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) 2014-2018 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
|
||
|
|
|
||
|
|
|