[Python-Dev] Remaining decisions on PEP 471 -- os.scandir()

[Victor Stinner]

2014-07-21 18:48 GMT+02:00 Ben Hoyt <benhoyt at gmail.com>:
>> By the way, DirEntry constructor is not documented in the PEP. Should
>> we document it? It might be a way to "invalidate the cache":
>
> I would prefer not to, just to keep things simple. Similar to creating
> os.stat_result() objects ... you can kind of do it (see scandir.py),
> but it's not recommended or even documented. The entire purpose of
> DirEntry objects is so scandir can produce them, not for general use.
>
>> entry = DirEntry(os.path.dirname(entry.path), entry.name)
>>
>> Maybe it is an abuse of the API. A clear_cache() method would be less
>> ugly :-) But maybe Ben Hoyt does not want to promote keeping DirEntry
>> for a long time?
>>
>> Another question: should we expose DirEntry type directly in the os
>> namespace? (os.DirEntry)
>
> Again, I'd rather not expose this. It's quite system-specific (see the
> different system versions in scandir.py), and trying to combine this,
> make it consistent, and document it would be a bit of a pain, and also
> possibly prevent future modifications (because then the parts of the
> implementation would be set in stone).

We should mimic os.stat() and os.stat_result: os.stat_result symbol
exists in the os namespace, but the type constructor is not
documented. No need for extra protection like not adding the type in
the os module, or adding a "_" prefix to the name.

By the way, it's possible to serialize a stat_result with pickle.

See also my issue "Enhance doc of os.stat_result":
http://bugs.python.org/issue21813

> I'm not really opposed to a clear_cache() method -- basically it'd set
> _lstat and _stat and _d_type to None internally. However, I'd prefer
> to keep it as is, and as the PEP says: (...)

Ok, agreed.

Victor