I just checked and werkzeug uses the same implementation as Django & pip.

2014-04-06 14:31 GMT+04:00 Omer Katz <report@bugs.python.org>:

>
> Omer Katz added the comment:
>
> The default implementation should simple:
> Once the property is accessed for the first time calculate the result and
> never calculate again.
> It's what both Django & pip uses.
> You can add an optional TTL.
> There aren't any other features I can come up with that are common enough.
> If needed, one can inherit from cached_property and do whatever is needed.
> Eric, Why don't you think a C implementation is needed? It's a simple
> operation for sure but it is meant to increase runtime efficiency.
>
> 2014-04-05 1:11 GMT+04:00 Éric Araujo <report@bugs.python.org>:
>
> >
> > Éric Araujo added the comment:
> >
> > It could make sense to add clean, working recipes to e.g. the functools
> > documentation.  The cached_property in the wiki uses a TTL, other like
> > Pyramid's reify decorator make properties that ensure the fget function
> is
> > called only once per instance, and there may be subtly different variants
> > out there.  I don't know if there's a universally useful variant that
> > should be added to the sdlib right now.  (I don't think a C
> implementation
> > is needed.)
> >
> > On a related note, the Python docs about desciptors may be missing
> > entry-level explanations, as described here:
> > http://me.veekun.com/blog/2012/05/23/python-faq-descriptors/
> >
> > ----------
> > nosy: +eric.araujo, rhettinger
> >
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> > <http://bugs.python.org/issue21145>
> > _______________________________________
> >
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