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Title: argparse: terminal width is not detected properly
Type: enhancement Stage: resolved
Components: Library (Lib) Versions: Python 3.8
Status: closed Resolution: fixed
Dependencies: 13609 Superseder:
Assigned To: Nosy List: berker.peksag, bethard, denilsonsa, flox, jmehnle, paul.j3, zbysz
Priority: normal Keywords: patch

Created on 2011-09-24 22:07 by zbysz, last changed 2022-04-11 14:57 by admin. This issue is now closed.

File name Uploaded Description Edit
issue13041.patch zbysz, 2012-02-22 15:36 use shutil.get_terminal_size() review
Pull Requests
URL Status Linked Edit
PR 8459 merged berker.peksag, 2018-07-25 09:11
Messages (12)
msg144507 - (view) Author: Zbyszek Jędrzejewski-Szmek (zbysz) * Date: 2011-09-24 22:07
COLUMNS is a shell variable (updated whenever the window size
changes), that usually isn't exported to programs. Therefore checking
for COLUMNS in sys.environ will not work in the majority of cases. The
proper check is to use the TIOCGWINSZ ioctl on stdout.
Why COLUMNS is not exported? Because it can change during the lifetime
of a program. Therefore it is better to use the dynamic ioctl.
msg144521 - (view) Author: Zbyszek Jędrzejewski-Szmek (zbysz) * Date: 2011-09-25 10:01
I see that adding a separate module was proposed in issue #8408, which was rejected/closed. I don't have the rights to reopen, so I'll continue here.

#8408 was proposing a new module, which seems a bit overkill, since the implementation for unix and windows is about 20 lines.

I'm attaching a second version of the patch which works on windows (tested with python3.2.2 on XP). Thanks to techtonik for pointing to a windows imlementation.
msg144523 - (view) Author: Denilson Figueiredo de Sá (denilsonsa) Date: 2011-09-25 14:18
> #8408 was proposing a new module, which seems a bit overkill

If a module seems overkill, then maybe add this useful function to os module. Don't leave it private to argparse module. Maybe something along these lines:

    >>> import os
    >>> print(os.get_terminal_size())
    (80, 25)

Why do I believe a module could be better? Because I'd also like some way to detect when the terminal size has changed (without probing it all the time).
msg149531 - (view) Author: Steven Bethard (bethard) * (Python committer) Date: 2011-12-15 11:08
I'd feel more comfortable with the argparse fix if it were simply calling "os.get_terminal_size()". I recommend that you:

* Create a new issue called, say "add os.get_terminal_size()" proposing just the single method.

* Add that issue to the Dependencies of this issue.

Once that is fixed, then the argparse fix should be simple.
msg149587 - (view) Author: Denilson Figueiredo de Sá (denilsonsa) Date: 2011-12-16 01:05
Issue #13609 created, but I don't have permission to edit the dependencies.
msg150728 - (view) Author: Zbyszek Jędrzejewski-Szmek (zbysz) * Date: 2012-01-06 13:04
New version to use after #13609 is implemented: patch2.diff
msg153961 - (view) Author: Zbyszek Jędrzejewski-Szmek (zbysz) * Date: 2012-02-22 15:36
OK, I guess that this could now be closed, since 13609 has been commited.
(It is currently reopened, but the proposed tweaks wouldn't influence
the usage in argparse, even if accepted).

I'm attaching a patch which updates the tests to the new $COLUMNS logic.
Previously, unsetting COLUMNS would fix the width on 80, now setting
COLUMNS=80 is the proper way to do this.
msg223222 - (view) Author: Mark Lawrence (BreamoreBoy) * Date: 2014-07-16 15:29
@Paul the attached patch is extremely simple and follows the work on #13609.  Is it okay with you if the patch was committed?
msg223298 - (view) Author: paul j3 (paul.j3) * (Python triager) Date: 2014-07-16 23:30
The latest patch, using _shutil.get_terminal_size(), looks fine.  

It lets environ['COLUMNS'] have priority over the end user's terminal width, as demonstrated by the change to test_argparse.  test_argparse doesn't test changing the actual terminal size, but I imagine that would be a pain to implement.
msg223809 - (view) Author: paul j3 (paul.j3) * (Python triager) Date: 2014-07-24 05:24
For now the user could add this to his module:

    import os, shutil
    os.environ['COLUMNS'] = str(shutil.get_terminal_size().columns)
msg315274 - (view) Author: Julian Mehnle (jmehnle) Date: 2018-04-13 23:58
What's holding up the merging of this patch?
msg322365 - (view) Author: Berker Peksag (berker.peksag) * (Python committer) Date: 2018-07-25 15:23
New changeset 74102c9a5f2327c4fc47feefa072854a53551d1f by Berker Peksag in branch 'master':
bpo-13041: Use shutil.get_terminal_size() in argparse.HelpFormatter (GH-8459)
Date User Action Args
2022-04-11 14:57:21adminsetgithub: 57250
2018-07-25 15:24:20berker.peksagsetstatus: open -> closed
stage: patch review -> resolved
resolution: fixed
versions: + Python 3.8, - Python 3.5
2018-07-25 15:23:47berker.peksagsetmessages: + msg322365
2018-07-25 09:11:28berker.peksagsetpull_requests: + pull_request7983
2018-04-14 00:09:54BreamoreBoysetnosy: - BreamoreBoy
2018-04-13 23:58:03jmehnlesetnosy: + jmehnle
messages: + msg315274
2014-07-24 05:24:13paul.j3setmessages: + msg223809
2014-07-16 23:30:18paul.j3setmessages: + msg223298
2014-07-16 20:15:50berker.peksagsetnosy: + berker.peksag

type: behavior -> enhancement
versions: + Python 3.5, - Python 3.3
2014-07-16 15:29:44BreamoreBoysetnosy: + paul.j3, BreamoreBoy
messages: + msg223222
2012-02-22 15:36:48zbyszsetfiles: - patch2.diff
2012-02-22 15:36:42zbyszsetfiles: - patch1.1.diff
2012-02-22 15:36:33zbyszsetfiles: - patch1.diff
2012-02-22 15:36:05zbyszsetfiles: + issue13041.patch

messages: + msg153961
2012-01-06 13:04:38zbyszsetfiles: + patch2.diff

messages: + msg150728
2011-12-16 12:12:27giampaolo.rodolasetdependencies: + Add "os.get_terminal_size()" function
versions: - Python 2.7, Python 3.2
2011-12-16 01:05:43denilsonsasetmessages: + msg149587
2011-12-15 11:08:45bethardsetmessages: + msg149531
versions: + Python 2.7, Python 3.2
2011-10-27 21:55:35floxsetnosy: + flox
stage: patch review

versions: - Python 3.4
2011-09-25 14:18:42denilsonsasetmessages: + msg144523
2011-09-25 10:02:00zbyszsetfiles: + patch1.1.diff

messages: + msg144521
2011-09-25 02:40:21denilsonsasetnosy: + denilsonsa
2011-09-24 22:13:22ezio.melottisetnosy: + bethard
2011-09-24 22:12:15ezio.melottilinkissue13042 superseder
2011-09-24 22:07:18zbyszcreate