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

[Victor Stinner]

2014-07-14 2:33 GMT+02:00 Ben Hoyt <benhoyt at gmail.com>:
> If we go with Victor's link-following .is_dir() and .is_file(), then
> we probably need to add his suggestion of a follow_symlinks=False
> parameter (defaults to True). Either that or you have to say
> "stat.S_ISDIR(entry.lstat().st_mode)" instead, which is a little bit
> less nice.

You forgot one of my argument: we must have exactly the same API than
os.path.is_dir() and pathlib.Path.is_dir(), because it would be very
confusing (source of bugs) to have a different behaviour.

Since these functions don't have any parameter (there is no such
follow_symlink(s) parameter), I'm opposed to the idea of adding such
parameter.

If you really want to add a follow_symlink optional parameter, IMO you
should modify all os.path.is*() functions and all pathlib.Path.is*()
methods to add it there too. Maybe if nobody asked for this feature
before, it's because it's not useful in practice. You can simply test
explicitly is_symlink() before checking is_dir().

Well, let's imagine DirEntry.is_dir() does not follow symlinks. How do
you test is_dir() and follow symlinks?
"stat.S_ISDIR(entry.stat().st_mode)" ? You have to import the stat
module, and use the ugly C macro S_ISDIR().

Victor