[Python-Dev] PEP 0424: A method for exposing a length hint

Lennart Regebro regebro at gmail.com
Tue Jul 17 16:02:05 CEST 2012


On Sun, Jul 15, 2012 at 1:28 AM, Alexandre Zani
<alexandre.zani at gmail.com> wrote:
> I'm +1 on not having a public API for this. Ultimately the contract
> for a length hint will depend heavily upon what you need it for. Some
> applications would require a length hint to be an "at least" others an
> "at most" and others something else entirely. Given that the contract
> here appears to be >=0, I don't think the length hint is particularly
> useful to the public at large.

Other possible related uses could be to get an approximate number of
results for a query without having to actually go through the whole
query, useful for databases and search engines. But then you *do* want
__len__ as well, so that also doesn't fit with the current PEP.

But maybe that's a completely different usecase, even though it seems
related to me?

//Lennart


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