Support os.walk(dir_fd=) and os.fwalk(dir_fd=)

[Georg]

http://bugs.python.org/review/15177/diff/5233/Lib/os.py
File Lib/os.py (right):

http://bugs.python.org/review/15177/diff/5233/Lib/os.py#newcode519
Lib/os.py:519: supports_dir_fd.add(fwalk)
Please don't add this.  It doesn't make any sense since you can't test for it.

[larry]

http://bugs.python.org/review/15177/diff/5233/Lib/os.py
File Lib/os.py (right):

http://bugs.python.org/review/15177/diff/5233/Lib/os.py#newcode519
Lib/os.py:519: supports_dir_fd.add(fwalk)
On 2012/06/25 10:43:12, Georg wrote:
> Please don't add this.  It doesn't make any sense since you can't test for it.

Done.

[storchaka]

http://bugs.python.org/review/15177/diff/5238/Doc/library/os.rst
File Doc/library/os.rst (right):

http://bugs.python.org/review/15177/diff/5238/Doc/library/os.rst#newcode2218
Doc/library/os.rst:2218: ``(dirpath, dirnames, filenames, dirfd)``, and it
supports ``dir_fd``.
But walk also supports dir_fd.

http://bugs.python.org/review/15177/diff/5238/Lib/os.py
File Lib/os.py (right):

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode341
Lib/os.py:341: return False
Should onerror handler be used?

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode419
Lib/os.py:419: close(close_me)
What if error happens on close?

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode446
Lib/os.py:446: if followlinks or not islink(new_path):
st.S_ISLINK(stat(name, dir_fd=close_me).st_mode) ?

[larry]

This isn't happening for 3.3 anyway, but maybe it'll go in for 3.4.  (I'll talk
to the 3.4 RM.)

http://bugs.python.org/review/15177/diff/5238/Doc/library/os.rst
File Doc/library/os.rst (right):

http://bugs.python.org/review/15177/diff/5238/Doc/library/os.rst#newcode2218
Doc/library/os.rst:2218: ``(dirpath, dirnames, filenames, dirfd)``, and it
supports ``dir_fd``.
On 2012/06/25 14:08:10, storchaka wrote:
> But walk also supports dir_fd.
Wishful thinking for now ;-) but, Done.

http://bugs.python.org/review/15177/diff/5238/Lib/os.py
File Lib/os.py (right):

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode341
Lib/os.py:341: return False
On 2012/06/25 14:08:10, storchaka wrote:
> Should onerror handler be used?

I have a much better implementation, so this one is best forgotten.  The new
implementation is just seven lines right at the top of os.walk, and looks
basically like this:

if they pass in dir_fd:
  if fwalk is unavailable
     throw NotImplementedError
  for tuple in fwalk(args):
     yield tuple[:-1]
  return

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode419
Lib/os.py:419: close(close_me)
On 2012/06/25 14:08:10, storchaka wrote:
> What if error happens on close?
Obviated by new implementation.

http://bugs.python.org/review/15177/diff/5238/Lib/os.py#newcode446
Lib/os.py:446: if followlinks or not islink(new_path):
On 2012/06/25 14:08:10, storchaka wrote:
> st.S_ISLINK(stat(name, dir_fd=close_me).st_mode) ?
Obviated by new implementation.