First, just to clarify a couple of points. > 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.
Actually, I specifically included that argument. It's item (b) in the list in my original message yesterday. :-) > 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(). Yeah, this is fair enough. > 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(). No, you don't actually need stat/S_ISDIR in that case -- if DirEntry.is_dir() does not follow symlinks, you just say: entry.is_symlink() and os.path.isdir(entry.full_name) Or for the full test: (entry.is_symlink() and os.path.isdir(entry.full_name)) or entry.is_dir() On the other hand, if DirEntry.is_dir() does follow symlinks per your proposal, then to do is_dir without following symlinks you need to use DirEntry. lstat() like so: stat.S_ISDIR(entry.lstat().st_mode) So from this perspective it's somewhat nicer to have DirEntry.is_X() not follow links and use DirEntry.is_symlink() and os.path.isX() to supplement that if you want to follow links. I think Victor has a good point re 92% of the stdlib calls that use listdir and isX do follow links. However, I think Tim Delaney makes some good points above about the (not so) safety of scandir following symlinks by default -- symlinks to network file systems, nonexist files, or huge directory trees. In that light, this kind of thing should be opt-*in*. I guess I'm still slightly on the DirEntry-does-not-follow-links side of the fence, due to the fact that it's a method on the *directory entry* object, due to simplicity of implementation, and due to Tim Delaney's "it should be safe by default" point above. However, we're *almost* bikeshedding at this point, and I think we just need to pick one way or the other. It's straight forward to implement one in terms of the other in each case. -Ben _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
