Issue 21827: textwrap.dedent() fails when largest common whitespace is a substring of smallest leading whitespace (original) (raw)

Issue21827

process

Created on 2014-06-22 16:44 by robertjli, last changed 2022-04-11 14:58 by admin. This issue is now closed.

| Repositories containing patches | | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | | | | https://bitbucket.org/bloomberg/cpython#issue21827 | | | |

Messages (16)
msg221277 - (view)	Author: Robert Li (robertjli) *	Date: 2014-06-22 16:44
Failing test case: " \tboo\n \tghost" expected: " \tboo\n\tghost" returns: " \tboo\n \tghost"
msg221281 - (view)	Author: Raymond Hettinger (rhettinger) *	Date: 2014-06-22 17:18
Confirmed that the test case fails on 2.7, 3.4, and 3.5
msg221282 - (view)	Author: Raymond Hettinger (rhettinger) *	Date: 2014-06-22 17:28
This one isn't hard. Would you like to make a patch? If not, I get to it this evening.
msg221283 - (view)	Author: YJ Chen (yjchen)	Date: 2014-06-22 17:30
Hi Raymond- Rob and I have a patch ready. We are figuring out how to upload/submit it. New to this... :)
msg221287 - (view)	Author: Robert Li (robertjli) *	Date: 2014-06-22 18:03
YJ and I are adding a patch and an additional test.
msg221292 - (view)	Author: Zachary Ware (zach.ware) *	Date: 2014-06-22 18:28
Raymond confirmed that the issue exists on 2.7 and 3.4, so we'll keep those in the version list. Whoever makes the commit will take care of backporting the patch, though.
msg224544 - (view)	Author: Daniel Eriksson (puppet) *	Date: 2014-08-02 09:12
Tested and it works fine on CentOS 6.4 in 2.7, 3.4 and 3.5
msg224547 - (view)	Author: Raymond Hettinger (rhettinger) *	Date: 2014-08-02 10:45
I've got it from here.
msg253593 - (view)	Author: John Mark Vandenberg (jayvdb) *	Date: 2015-10-28 08:43
Not surprising also occurs on Python 3.2, 3.3, & 3.6. I'm not sure whether fixes like this are suitable to be merged into 3.2/3.3.(is there a document describing this?)
msg253596 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2015-10-28 11:04
LGTM. But the implementation can be more efficient. Here is optimized patch. 34e88a05562f.diff: $ ./python -m timeit -s 'import textwrap; s = "{0} x\n{0}\tx\n".format(" "*100)' -- 'textwrap.dedent(s)' 10000 loops, best of 3: 87.5 usec per loop $ ./python -m timeit -s 'import textwrap; s = "{0} x\n{0}\tx\n".format(" "*1000)' -- 'textwrap.dedent(s)' 1000 loops, best of 3: 780 usec per loop .patch: $ ./python -m timeit -s 'import textwrap; s = "{0} x\n{0}\tx\n".format(" "*100)' -- 'textwrap.dedent(s)' 10000 loops, best of 3: 51 usec per loop $ ./python -m timeit -s 'import textwrap; s = "{0} x\n{0}\tx\n".format(" "*1000)' -- 'textwrap.dedent(s)' 1000 loops, best of 3: 395 usec per loop
msg253600 - (view)	Author: R. David Murray (r.david.murray) *	Date: 2015-10-28 14:41
It's one of the PEPs (I forget which one). We only apply non-security fixes to the most recent non-development branch...except that for now we also apply bug fixes to 2.7. So, 2.7, 3.5, and 3.6 are the targets for this issue.
msg253605 - (view)	Author: Raymond Hettinger (rhettinger) *	Date: 2015-10-28 15:46
Serhiy, your way looks best. Go ahead with it.
msg253609 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2015-10-28 17:14
I thought that 3.4 will switch to "security fixes only" mode after releasing first release since releasing 3.5.0. It was so with 3.2 and 3.3.
msg253612 - (view)	Author: R. David Murray (r.david.murray) *	Date: 2015-10-28 17:37
You are right, I'd forgotten we hadn't done 3.4 final yet.
msg253620 - (view)	Author: Roundup Robot (python-dev)	Date: 2015-10-28 19:46
New changeset faeeb8dbe432 by Serhiy Storchaka in branch '3.4': Issue #21827: Fixed textwrap.dedent() for the case when largest common https://hg.python.org/cpython/rev/faeeb8dbe432 New changeset c307ae7b3d9f by Serhiy Storchaka in branch '2.7': Issue #21827: Fixed textwrap.dedent() for the case when largest common https://hg.python.org/cpython/rev/c307ae7b3d9f New changeset 3f29be82c944 by Serhiy Storchaka in branch '3.5': Issue #21827: Fixed textwrap.dedent() for the case when largest common https://hg.python.org/cpython/rev/3f29be82c944 New changeset 8d3932671e48 by Serhiy Storchaka in branch 'default': Issue #21827: Fixed textwrap.dedent() for the case when largest common https://hg.python.org/cpython/rev/8d3932671e48
msg253621 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2015-10-28 19:50
Thank you Robert for your report and patch.