Big speed boost in os.walk in Python 2.5

Fredrik Lundh fredrik at
Fri Oct 13 18:05:56 CEST 2006

looping wrote:

> Results on Windows XP after some run to fill the disk cache (with
> ~59000 files and ~3500 folders):
> Python 2.4.3 : 45s
> Python 2.5 : 10s
> Very nice, but somewhat strange...
> Is Python 2.4.3 os.walk buggy ???

No.  A few "os" function are now implemented in terms of Windows API:s, 
instead of using Microsoft C's POSIX compatibility layer.  This includes 
os.stat(), which is what isdir() uses to check if something is a 
directory.  The code was rewritten to work around problems with 
timestamps, so the speedup is purely a side effect.

> Is this results only valid in Windows or *nix system show the same
> difference ?

On Unix system, Python uses POSIX API:s, not Windows API:s.

> The profiler show that most of time is spend in ntpath.isdir and this
> function is *a lot* faster in Python 2.5.

Why are you asking if something's buggy when you've already figured out 
what's been improved?

> Maybe this improvement could be backported in Python 2.4 branch for the
> next release ?

It's not really broken, so that's not very likely.


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