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

[Ben Hoyt]

> I remember a pending question on python-dev:
>
> - Martin von Loewis asked if the scandir generator would have send()
> and close() methods as any Python generator. I didn't see a reply on
> the mailing (nor in the PEP).

Good call. Looks like you're referring to this message:
https://mail.python.org/pipermail/python-dev/2014-July/135324.html

I'm not actually familiar with the purpose of .close() and
.send()/.throw() on generators. Do you typically call these functions
manually, or are they called automatically by the generator protocol?

> It is not clear to me which methods share the cache.
>
> On UNIX, is_dir() and is_file() call os.stat(); whereas lstat() and
> is_symlink() call os.lstat().
>
> If os.stat() says that the file is not a symlink, I guess that you can
> use os.stat() result for lstat() and is_symlink() methods?
>
> In the worst case, if the path is a symlink, would it be possible that
> os.stat() and os.lstat() become "inconsistent" if the symlink is
> modified between the two calls? If yes, I don't think that it's an
> issue, it's just good to know it.
>
> For symlinks, readdir() returns the status of the linked file or of the symlink?

I think you're misunderstanding is_dir() and is_file(), as these don't
actually call os.stat(). All DirEntry methods either call nothing or
os.lstat() to get the stat info on the entry itself (not the
destination of the symlink). In light of this, I don't think what
you're describing above is an issue.

-Ben