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sys.executable generating canonical path #58296
Description
| BPO | 14088 |
|---|---|
| Nosy | @pitrou, @vstinner, @ned-deily, @merwok, @akheron, @iritkatriel |
| Files |
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 = None
created_at = <Date 2012-02-22.16:36:56.658>
labels = ['type-bug', 'library', '3.9', '3.10', '3.11']
title = 'sys.executable generating canonical path'
updated_at = <Date 2021-08-31.21:58:44.018>
user = 'https://bugs.python.org/alvesjnr'bugs.python.org fields:
activity = <Date 2021-08-31.21:58:44.018>
actor = 'vstinner'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2012-02-22.16:36:56.658>
creator = 'alvesjnr'
dependencies = []
files = ['24604', '24607']
hgrepos = []
issue_num = 14088
keywords = ['patch']
message_count = 15.0
messages = ['153970', '153993', '154008', '154009', '154010', '154012', '154015', '154019', '154108', '154448', '400435', '400618', '400619', '400651', '400787']
nosy_count = 7.0
nosy_names = ['pitrou', 'vstinner', 'ned.deily', 'eric.araujo', 'petri.lehtinen', 'alvesjnr', 'iritkatriel']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue14088'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']
Activity
alvesjnr commentedon Feb 22, 2012
Hi all,
As it is my first time here, I'll try to explay step-by-step why I'm providing this path, and why I think that it is changing something that I believe that is not correct.
First of all, I was trying to run one individual test, as the dev guide says:
./python -m test -v test_sys
but, instead of run this test from the root directory of the project, I run it from ./Lib/test, so I did:
../../python -m test -v test_sys
and it returned an error. The reason is that my sys.executable was not an abspath. When I went to see why it is different, I get this value to sys.executable:
sys.executable -> '/home/antonio/Projects/cpython/Lib/test/../../python'
I'm not sure if I'm thinking write, but for me don't look nice to have this value as sys.executable, once the real path should be:
'/home/antonio/Projects/cpython/python'
So I'm providing a paatch that do exactly this.
Hope you enjoy
pitrou commentedon Feb 22, 2012
This is unfortunately wrong since it will fail in the face of symlinks.
(if "foo" is a symlink to another directory, then "foo/../bar" is not the same thing as "bar")
vstinner commentedon Feb 22, 2012
We can use realpath() if the function is available. Something similar is already done for sys.argv[0]. We should also use GetFullPathNameW() on Windows.
vstinner commentedon Feb 22, 2012
See also the issue bpo-13402.
pitrou commentedon Feb 22, 2012
GetFullPathName() is an abspath() equivalent. For realpath() you want
GetFinalPathNameByHandle(), aka. _nt.getfinalpathname().
vstinner commentedon Feb 22, 2012
Ah? ntpath.realpath() uses nt._getfullpathname(). Is it a bug in ntpath?
pitrou commentedon Feb 22, 2012
Probably:
vstinner commentedon Feb 22, 2012
Ok, I opened the issue bpo-14094.
merwok commentedon Feb 24, 2012
I wonder if the doc for sys.executable should mention that .. segments may be present.
akheron commentedon Feb 27, 2012
Éric Araujo wrote:
Once this is fixed, it should say that .. segments may be present if
there's realpath() is not available.
iritkatriel commentedon Aug 27, 2021
This is still unresolved:
iritkatriel@Irits-MBP Lib % pwd
/Users/iritkatriel/src/cpython-1/Lib
iritkatriel@Irits-MBP Lib % ../python.exe -m test -v test_sys
[snipped]
======================================================================
FAIL: test_executable (test.test_sys.SysModuleTest)
----------------------------------------------------------------------
Traceback (most recent call last): File "/Users/iritkatriel/src/cpython-1/Lib/test/test_sys.py", line 692, in test_executable self.assertEqual(os.path.abspath(sys.executable), sys.executable) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ AssertionError: '/Users/iritkatriel/src/cpython-1/python.exe' != '/Users/iritkatriel/src/cpython-1/Lib/../python.exe' - /Users/iritkatriel/src/cpython-1/python.exe + /Users/iritkatriel/src/cpython-1/Lib/../python.exe ? +++++++vstinner commentedon Aug 30, 2021
test_sys:
IMO the test is wrong. It must test: test.assertTrue(os.path.isabs(sys.executable)).
The path is not required to be normalized.
vstinner commentedon Aug 30, 2021
I'm talking about the current implementation.
I'm not against making Python even better: attempt to normalize the path ;-)
ned-deily commentedon Aug 30, 2021
I would be very cautious about doing that. I'm pretty sure it would break some existing code.
vstinner commentedon Aug 31, 2021
See also bpo-20443 "__code__. co_filename should always be an absolute path". I had a revert a change which affected sys.argv[0]:
commit a1a99b4
Author: Victor Stinner <vstinner@python.org>
Date: Mon Dec 9 17:34:02 2019 +0100
devdanzin commentedon Aug 10, 2026
Given the probability of breaking user code, setting as pending. Please revert if this is deemed desirable.