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

Victor Stinner victor.stinner at haypocalc.com
Thu Jun 9 11:05:17 CEST 2011

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."""

Victor

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