[Python-Dev] cpython (3.2): Fix #11583. Changed os.path.isdir to use GetFileAttributes instead of os.stat. (original) (raw)

Brian Curtin brian.curtin at gmail.com
Thu Jun 9 17:04:58 CEST 2011

On Thu, Jun 9, 2011 at 04:05, Victor Stinner <victor.stinner at haypocalc.com>wrote:

Le jeudi 09 juin 2011 à 08:16 +0200, Georg Brandl a écrit : > On 06/09/11 02:00, brian.curtin wrote: > > http://hg.python.org/cpython/rev/88e318166eaf > > changeset: 70713:88e318166eaf > > branch: 3.2 > > parent: 70700:0aa3064d1cef > > user: Brian Curtin <brian at python.org> > > date: Wed Jun 08 18:17:18 2011 -0500 > > summary: > > Fix #11583. Changed os.path.isdir to use GetFileAttributes instead of os.stat. > > > > By changing to the Windows GetFileAttributes API in nt.isdir we can figure > > out if the path is a directory without opening the file via os.stat. This has > > the minor benefit of speeding up os.path.isdir by at least 2x for regular > > files and 10-15x improvements were seen on symbolic links (which opened the > > file multiple times during os.stat). Since os.path.isdir is used in > > several places on interpreter startup, we get a minor speedup in startup time. > > > > files: > > Lib/ntpath.py | 13 ++++++++++ > > Misc/NEWS | 3 ++ > > Modules/posixmodule.c | 37 +++++++++++++++++++++++++++++++ > > 3 files changed, 53 insertions(+), 0 deletions(-) > > > > > > diff --git a/Lib/ntpath.py b/Lib/ntpath.py > > --- a/Lib/ntpath.py > > +++ b/Lib/ntpath.py > > @@ -672,3 +672,16 @@ > > def sameopenfile(f1, f2): > > """Test whether two file objects reference the same file""" > > return getfileinformation(f1) == getfileinformation(f2) > > + > > + > > +try: > > + # The genericpath.isdir implementation uses os.stat and checks the mode > > + # attribute to tell whether or not the path is a directory. > > + # This is overkill on Windows - just pass the path to GetFileAttributes > > + # and check the attribute from there. > > + from nt import isdir > > +except ImportError: > > + from genericpath import isdir as isdir > > + > > +def isdir(path): > > + return isdir(path) > > Not that it matters, but ISTM that this would be faster as > > try: > from nt import isdir as isdir > except ImportError: > pass

I would matter if isdir() had a docstring, but it doesn't :-) genericpath.isdir() has the following doc: def isdir(s): """Return true if the pathname refers to an existing directory."""

http://hg.python.org/lookup/d40609dd01e0 adds the docstring back in and redoes the imports as Georg mentioned, which is better. Thanks for having a look. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20110609/03852942/attachment.html>

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