Issue 13107: Text width in optparse.py can become negative (original) (raw)
Created on 2011-10-05 11:08 by adambyrtek, last changed 2022-04-11 14:57 by admin. This issue is now closed.
Messages (10)
Author: Adam Byrtek (adambyrtek)
Date: 2011-10-05 11:08
Code snippet from optparse.py:
344 self.help_position = min(max_len + 2, self.max_help_position) 345 self.help_width = self.width - self.help_position
Where self.width is initialized with the COLUMNS environment variable. On narrow terminals it can happen that self.help_position < self.width, leading to an exception in textwrap.py:
raise ValueError("invalid width %r (must be > 0)" % self.width)ValueError: invalid width -15 (must be > 0)
A reasonable workaround would be to trim part of the help text instead of causing an exception.
Author: Ezio Melotti (ezio.melotti) * 
Date: 2011-10-07 21:13
argparse has some similar code in Lib/argparse.py:489. Can you reproduce the problem with argparse? If you can't and argparse solved the problem already, we might adopt the same solution; if you can, it should be fixed there too.
Author: Serhiy Storchaka (serhiy.storchaka) *
Date: 2013-08-29 10:57
Yes, argparse has same problem.
import os, argparse p = argparse.ArgumentParser(prog='PROG') os.environ['COLUMNS'] = '16' print(p.format_help()) Traceback (most recent call last): File "", line 1, in File "/home/serhiy/py/cpython/Lib/argparse.py", line 2329, in format_help return formatter.format_help() File "/home/serhiy/py/cpython/Lib/argparse.py", line 276, in format_help help = self._root_section.format_help() File "/home/serhiy/py/cpython/Lib/argparse.py", line 206, in format_help func(*args) File "/home/serhiy/py/cpython/Lib/argparse.py", line 206, in format_help func(*args) File "/home/serhiy/py/cpython/Lib/argparse.py", line 514, in _format_action help_lines = self._split_lines(help_text, help_width) File "/home/serhiy/py/cpython/Lib/argparse.py", line 614, in _split_lines return _textwrap.wrap(text, width) File "/home/serhiy/py/cpython/Lib/textwrap.py", line 355, in wrap return w.wrap(text) File "/home/serhiy/py/cpython/Lib/textwrap.py", line 300, in wrap return self._wrap_chunks(chunks) File "/home/serhiy/py/cpython/Lib/textwrap.py", line 227, in _wrap_chunks raise ValueError("invalid width %r (must be > 0)" % self.width) ValueError: invalid width 0 (must be > 0)
Author: Elazar Gershuni (elazar) *
Date: 2013-09-01 21:10
I think in such case it is reasonable to fail silently, since the information will not be readable anyway. Is a patch like the attached acceptable? (Sorry, I am new here)
results:
import os, argparse; p = argparse.ArgumentParser(prog='PROG') os.environ['COLUMNS'] = '0' print(p.format_help()) usage: PROG
[-h]optional arguments: -h, --help
Author: Dmi Baranov (dmi.baranov) *
Date: 2013-09-02 18:33
I think "ugly look is better than silence" here. Elazar, can you touch a optparse too (with some tests - test.support.EnvironmentVarGuard context manager will be helpful here)?
Author: Serhiy Storchaka (serhiy.storchaka) *
Date: 2013-09-02 20:47
I think "ugly look is better than silence" here.
Agree. We have two possibilities:
Decrease an indentation. There is a lot of blank spaces below option's names.
Set some minimal width (10 or 20 characters) and let lines wrap out.
For better look we should use both methods.
Author: Elazar Gershuni (elazar) *
Date: 2013-09-11 18:42
ok. how about argparse_ugly.patch? below some width it simply won't do any wrapping.
(I hadn't touch optparse yet)
Author: Serhiy Storchaka (serhiy.storchaka) *
Date: 2013-09-12 21:56
Here is less ugly patch (for argparse and optparse). Instead of prohibiting wrapping at all for small width, it limits minimal width of formatted text. It try first decrease the indent for help.
Author: Roundup Robot (python-dev) 
Date: 2014-01-09 21:19
New changeset 779de7b4909b by Serhiy Storchaka in branch '2.7': Issue #13107: argparse and optparse no longer raises an exception when output http://hg.python.org/cpython/rev/779de7b4909b
New changeset c6c30b682e14 by Serhiy Storchaka in branch '3.3': Issue #13107: argparse and optparse no longer raises an exception when output http://hg.python.org/cpython/rev/c6c30b682e14
New changeset 48bcd03cd29f by Serhiy Storchaka in branch 'default': Issue #13107: argparse and optparse no longer raises an exception when output http://hg.python.org/cpython/rev/48bcd03cd29f
Author: Serhiy Storchaka (serhiy.storchaka) *
Date: 2014-01-09 21:27
Thank you Adam for your report. Thank you Elazar for your patch.
History
Date
User
Action
Args
2022-04-11 14:57:22
admin
set
github: 57316
2014-02-17 11:31:19
serhiy.storchaka
link
2014-01-09 21:27:18
serhiy.storchaka
set
status: open -> closed
messages: +
assignee: serhiy.storchaka
resolution: fixed
stage: patch review -> resolved
2014-01-09 21:19:16
python-dev
set
nosy: + python-dev
messages: +
2013-09-12 21:56:41
serhiy.storchaka
set
files: + argparse_less_ugly.patch
messages: +
stage: test needed -> patch review
2013-09-11 18:42:17
elazar
set
files: + argparse_ugly.patch
messages: +
2013-09-02 20:47:41
serhiy.storchaka
set
messages: +
2013-09-02 18:33:01
dmi.baranov
set
nosy: + dmi.baranov
messages: +
2013-09-01 21:10:53
elazar
set
files: + fixargparse.patch
nosy: + elazar
messages: +
keywords: + patch
2013-08-29 10:57:16
serhiy.storchaka
set
assignee: serhiy.storchaka -> (no value)
messages: +
versions: + Python 2.7, Python 3.3, Python 3.4
2013-08-26 09:17:40
serhiy.storchaka
set
assignee: serhiy.storchaka
nosy: + serhiy.storchaka
2013-08-17 14:08:52
ezio.melotti
set
keywords: + easy
stage: needs patch -> test needed
2011-10-09 23:07:36
ezio.melotti
set
2011-10-07 21:13:20
ezio.melotti
set
nosy: + ezio.melotti
messages: +
stage: needs patch
2011-10-05 11:08:22
adambyrtek
create