memoization library for python 2.7

balki picture balki · Aug 5, 2012 · Viewed 38.8k times · Source

I see that python 3.2 has memoization as a decorator in functools library. http://docs.python.org/py3k/library/functools.html#functools.lru_cache

Unfortunately it is not yet backported to 2.7. Is there any specific reason as why it is not available in 2.7? Is there any 3rd party library providing the same feature or should I write my own?

Answer

Paolo Moretti picture Paolo Moretti · Aug 8, 2012

Is there any specific reason as why it is not available in 2.7?

@Nirk has already provided the reason: unfortunately, the 2.x line only receive bugfixes, and new features are developed for 3.x only.

Is there any 3rd party library providing the same feature?

repoze.lru is a LRU cache implementation for Python 2.6, Python 2.7 and Python 3.2.

Documentation and source code are available on GitHub.

Simple usage:

from repoze.lru import lru_cache

@lru_cache(maxsize=500)
def fib(n):
    if n < 2:
        return n
    return fib(n-1) + fib(n-2)