Object Cacher

Simple cacher for your objects. Store copy of objects in memory (or pickle in file) and returns copy of that objects. Function arguments it is a cache key.

>>> from object_cacher import ObjectCacher >>> @ObjectCacher(timeout=5) ... def test(*args): ... print ('Real call') ... return args ... >>> test(1,2,3) Real call (1, 2, 3)

>>> test(1,2,3) (1, 2, 3)

>>> test(1,2,3,4) Real call (1, 2, 3, 4)

>>> test(1,2,3,4) ... (1, 2, 3, 4)

Makes cache for results of hard functions or methods. For example you have remote RESTful api with a lot of dictionaries. You may cache it:

>>> from urllib import urlopen >>> from object_cacher import ObjectCacher >>> @ObjectCacher(timeout=60) ... def get_api(): ... print "This real call" ... return urlopen('https://api.github.com/').read() ... >>> get_api() This real call '{"current_user_url":"https://api.github.com/user", ...' >>> get_api() '{"current_user_url":"https://api.github.com/user", ...'

As result you made http request only once.

For methods you may use it like this:

>>> from urllib import urlopen >>> from object_cacher import ObjectCacher >>> class API(object): ... @ObjectCacher(timeout=60, ignore_self=True) ... def get_methods(self): ... print "Real call" ... return urlopen('https://api.github.com/').read() ... >>> a = API() >>> a.get_methods() Real call '{"current_user_url":"https://api.github.com/user", ...' >>> b = API() >>> b.get_methods() '{"current_user_url":"https://api.github.com/user", ...'

If ignore_self parameter is set, cache will be shared by all instances. Otherwise cache for instances will be split.

Also you may use persistent cache. The "ObjectPersistentCacher" class-decorator makes file-based pickle-serialized cache storage. When you want to keep cache after rerun you must determine cache id:

>>> from urllib import urlopen >>> from object_cacher import ObjectCacher >>> class API(object): ... @ObjectPersistentCacher(timeout=60, ignore_self=True, oid='com.github.api.listofmethods') ... def get_methods(self): ... print "Real call" ... return urlopen('https://api.github.com/').read() ... >>> a = API() >>> a.get_methods() Real call '{"current_user_url":"https://api.github.com/user", ...' >>> b = API() >>> b.get_methods() '{"current_user_url":"https://api.github.com/user", ...'

That is keep cache after rerun.

You may change cache dir for ObjectPersistentCacher via changing 'CACHE_DIR' class-property.

>>> ObjectPersistentCacher.CACHE_DIR = '/var/tmp/my_cache'

Installation

You may install from pypi

pip install object_cacher

or manual

python setup.py install