os.makedirs - robust against partial path

[jimjjewett]

BPO	1314067
Nosy	@birkenfeld
Files	os.py.patch: os.py patch - more robust makedirs

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2006-12-09.09:26:59.000>
created_at = <Date 2005-10-05.17:08:06.000>
labels = ['library']
title = 'os.makedirs - robust against partial path'
updated_at = <Date 2006-12-09.09:26:59.000>
user = 'https://bugs.python.org/jimjjewett'

bugs.python.org fields:

activity = <Date 2006-12-09.09:26:59.000>
actor = 'georg.brandl'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2005-10-05.17:08:06.000>
creator = 'jimjjewett'
dependencies = []
files = ['6812']
hgrepos = []
issue_num = 1314067
keywords = ['patch']
message_count = 5.0
messages = ['48837', '48838', '48839', '48840', '48841']
nosy_count = 3.0
nosy_names = ['georg.brandl', 'jimjjewett', 'rbarran']
pr_nums = []
priority = 'normal'
resolution = 'rejected'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1314067'
versions = ['Python 2.4']

[jimjjewett]

os.py function makedirs is intended to create a
directory, including any required parent directories.

Unfortunately, at least on windows, it fails is some of
those parent directories already exist. This patch
says "if the directory I'm about to create is already an
existing directory, then pretend I succeeded and
continue with the next step."

[rbarran]

Logged In: YES
user_id=1207189

Hi,

Could you provide some example code that shows up the error?
If I understand you correctly, the following should fail:

import os
os.mkdir('c:/temp/a')
os.makedirs('c:/temp/a/b/c')

But it works fine on my WinXP pro SP2 machine.

[jimjjewett]

Logged In: YES
user_id=764593

slight misdiagnosis on my part -- it only fails if the 
*entire* directory tree already exists.  
 
"""
>>> os.makedirs('c:/temp/a/b/c')

>> os.makedirs('c:/temp/a/b/c')

Traceback (most recent call last):
  File "<pyshell#64>", line 1, in -toplevel-
    os.makedirs('c:/temp/a/b/c')
  File "C:\Python24\lib\orig_os.py", line 159, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: 'c:/temp/a/b/c'
"""

My use case was generating java files in the proper package

• and possibly regenerating them if something changed. I
  want to put them in the right directory, which will usually
  (but not always) already exist.

The patch still works, but I now wonder if it might be
better to put a guard at the top along the lines of "if
path.exists(name): return" (or something fancier to ensure
that it is a directory with appropriate permissions).

[rbarran]

Logged In: YES
user_id=1207189

I think that the current behavior of the function is correct.
It tries to mimic os.mkdir - if the dir to create ("c" in
your example) already exists, it will raise an error.
However, errors on intermediate dirs are ignored.
This makes sense, but I think the documentation is not clear
on this (or maybe I'm just slow :-)
BTW - there's another patch ([ 1239890 ] Prevent race
condition in os.makedirs) to rewrite the whole function and
it might make your patch in its current form obsolete.
Maybe your work can be merged into this other patch?

[birkenfeld]

I agree with rbarran. Closing as Rejected.