[Python-Dev] Updates to PEP 471, the os.scandir() proposal

[Paul Moore]

On 9 July 2014 14:22, Ben Hoyt <benhoyt at gmail.com> wrote:
>> So maybe the onerror function should also receive the DirEntry object
>> - which will only have the name and full_name attributes, but that's
>> all that is needed.
>
> That's an interesting idea -- though enough of a deviation from
> os.walk()'s onerror that I'm uncomfortable with it -- I'd rather just
> document that the onerror exception .filename is the full path name.

But the onerror exception will come from the lstat call, so it'll be a
raw OSError (unless scandir modifies it, which may be what you're
thinking of). And if so, aren't we at the mercy of what the OS module
gives us? That's why I said we can't guarantee it. I looked at the
documentation of OSError (in "Built In Exceptions"), and all it says
is "the filename" (unqualified). I'd expect that to be "whatever got
passed to the underlying OS API" - which may well be an absolute
pathname if we're lucky, but who knows? (I'd actually prefer it if
OSError guaranteed a full pathname, but that's a bigger issue...)

Paul