[Python-Dev] os.access on Windows

Tim Golden Tim.Golden at cbsoutdoor.co.uk
Fri May 20 10:38:24 CEST 2011

There's a thread on python-list at the moment:


which is discussing the validity of os.access results on
Windows. Now we've been here before: I raised issue2528
for a previous enquiry some years ago and proffered a patch
which uses the AccessCheck API to perform the equivalent check,
but didn't follow through.

Someone on the new thread is suggesting -- validly -- that the
docs should highlight the limitations of this call on Windows.
But the docs for that call are already fairly involved:


We seem to have a few options in increasing order of difficulty:

* Do nothing - inform the occasional enquirer of the situation and
  leave it at that.

* Update the docs to add something which describes what the function
  actually does on the Windows platform. (Whether or not we change any code).

* Apply the patch in issue2528 to 3.3 and maybe 2.7

* Leave os.access alone but offer alternative Windows-specific
  functionality in the os module or elsewhere, using essentially
  the code in the issue2528 patch.

As a side note, the pywin32 packages don't actually include AccessCheck
at the moment. (Which makes it slightly harder to explain to people
how they could do this check for themselves). It could probably be added
over there which might ease the burden over here.


Tim Golden
Very Senior Analyst Programmer

CBS Outdoor UK
Camden Wharf
28 Jamestown Road
T: 020 7482 3000
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