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Subject: Re: Lazy Attribute
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From: "Stefan H. Holek" <stefan@epy.co.at>
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Date: Fri, 16 Nov 2012 13:46:01 +0100
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On 16.11.2012, at 11:54, Andriy Kornatskyy wrote:

>> Subject: Re: Lazy Attribute
>> From: stefan@epy.co.at
>> Date: Fri, 16 Nov 2012 11:45:32 +0100
>> To: python-list@python.org
>>=20
>> On 16.11.2012, at 11:29, Steven D'Aprano wrote:
>>=20
>>> I'm very vaguely leaning towards this as the least-worst solution to
>>> invalidating the cached value:
>>>=20
>>> refresh(obj, 'attr') # pass the instance and the name
>>=20
>> This it exactly how lazy handles invalidation. =
http://lazy.readthedocs.org/en/latest/
>=20
> @property is a solution to evaluate something that is dynamic. =
@attribute is good for immutable objects. Even if we assume refresh is a =
good idea... how I would know when it is valid to `refresh`? What is =
criteria?
>=20
> Andriy

I had to implement invalidation anyway in order to write tests. I =
decided to expose the mechanism to keep users from having to invent =
their own SHOULD the need arise. I was not advocating invalidation in =
any way with my reply. All I wanted was to confirm the "least bad" =
solution. ;-)

Stefan

--=20
Stefan H. Holek
stefan@epy.co.at