persistent caching to memory, disk, or database
klepto extends python's
lru_cache to utilize different keymaps and
alternate caching algorithms, such as
While caching is meant for fast access to saved results,
has archiving capabilities, for longer-term storage.
klepto uses a
simple dictionary-sytle interface for all caches and archives, and all
caches can be applied to any python function as a decorator. Keymaps
are algorithms for converting a function's input signature to a unique
dictionary, where the function's results are the dictionary value.
y = f(x),
y will be stored in
klepto provides both standard and "safe" caching, where "safe" caches
are slower but can recover from hashing errors.
klepto is intended
to be used for distributed and parallel computing, where several of
the keymaps serialize the stored objects. Caches and archives are
intended to be read/write accessible from different threads and
klepto enables a user to decorate a function, save the
results to a file or database archive, close the interpreter,
start a new session, and reload the function and it's cache.
klepto is part of
pathos, a python framework for heterogeneous computing.
klepto is in active development, so any user feedback, bug reports, comments,
or suggestions are highly appreciated. A list of issues is located at https://github.com/uqfoundation/klepto/issues, with a legacy list maintained at https://uqfoundation.github.io/project/pathos/query.
klepto has standard and "safe" variants of the following:
lfu_cache- the least-frequently-used caching algorithm
lru_cache- the least-recently-used caching algorithm
mru_cache- the most-recently-used caching algorithm
rr_cache- the random-replacement caching algorithm
no_cache- a dummy caching interface to archiving
inf_cache- an infinitely-growing cache
klepto has the following archive types:
file_archive- a dictionary-style interface to a file
dir_archive- a dictionary-style interface to a folder of files
sqltable_archive- a dictionary-style interface to a sql database table
sql_archive- a dictionary-style interface to a sql database
hdfdir_archive- a dictionary-style interface to a folder of hdf5 files
hdf_archive- a dictionary-style interface to a hdf5 file
dict_archive- a dictionary with an archive interface
null_archive- a dictionary-style interface to a dummy archive
klepto provides the following keymaps:
keymap- keys are raw python objects
hashmap- keys are a hash for the python object
stringmap- keys are the python object cast as a string
picklemap- keys are the serialized python object
klepto also includes a few useful decorators providing:
The latest released version of
klepto is available from:
klepto is distributed under a 3-clause BSD license.
You can get the latest development version with all the shiny new features at: https://github.com/uqfoundation
If you have a new contribution, please submit a pull request.
Probably the best way to get started is to look at the documentation at
http://klepto.rtfd.io. Also see
klepto.tests for a set of scripts that
test the caching and archiving functionalities in
You can run the test suite with
python -m klepto.tests. The
source code is also generally well documented, so further questions may
be resolved by inspecting the code itself. Please feel free to submit
a ticket on github, or ask a question on stackoverflow (@Mike McKerns).
If you would like to share how you use
klepto in your work, please send
an email (to mmckerns at uqfoundation dot org).
If you use
klepto to do research that leads to publication, we ask that you
acknowledge use of
klepto by citing the following in your publication::
Michael McKerns and Michael Aivazis, "pathos: a framework for heterogeneous computing", 2010- ; https://uqfoundation.github.io/project/pathos