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From: dieter <dieter@handshake.de>
Newsgroups: comp.lang.python
Subject: Re: Static caching property
Date: Tue, 22 Mar 2016 09:30:03 +0100
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Xref: csiph.com comp.lang.python:105454

"Joseph L. Casale" <jcasale@activenetwerx.com> writes:
> ...
> I need to cache the results of a method on a class across all instances.

If a method call on any instance defines the return value for
all instances, then this method likely should be a class method --
and use a class attribute to store the result -- something like this:

    class C(object):

    _cache = {}

    @classmethod
    def f(cls, ...):
      ... determine cache key `key` ...
      v = cls._cache.get(key)
      if v is None:
         v = cls._cache[key] = ...
      return v

It will work also without the "@classmethod".