I thought of this exact comment when I read the "bug fix considered a regression."
On Tue, Jan 6, 2015 at 2:41 PM, Guido van Rossum <gu...@python.org> wrote: > There's an obligatory XKCD reference for this: http://xkcd.com/1172/ > > On Tue, Jan 6, 2015 at 12:25 PM, Terry Reedy <tjre...@udel.edu> wrote: > >> On 1/6/2015 7:39 AM, Victor Stinner wrote: >> >>> More context: >>> >>> 2014-12-19 12:43 GMT+01:00 anatoly techtonik <techto...@gmail.com>: >>> >>>> https://github.com/nickstenning/honcho/pull/121 >>>> >>> >>> The link mentions the following changeset: >>> --- >>> changeset: 93122:1a3143752db2 >>> branch: 2.7 >>> parent: 93112:927cca0b9337 >>> user: R David Murray <rdmur...@bitdance.com> >>> date: Fri Oct 17 20:07:08 2014 -0400 >>> files: Lib/argparse.py Lib/test/test_argparse.py Misc/NEWS >>> description: >>> #9351: set_defaults on subparser is no longer ignored if set on parent. >>> >>> Before, if a default was set on the parent parser, any default for that >>> variable set via set_defaults on a subparser would be ignored. Now >>> the subparser set_defaults is honored. >>> >>> Patch by Jyrki Pullianinen. >>> >>> >>> diff -r 927cca0b9337 -r 1a3143752db2 Lib/argparse.py >>> --- a/Lib/argparse.py Fri Oct 17 16:20:15 2014 -0500 >>> +++ b/Lib/argparse.py Fri Oct 17 20:07:08 2014 -0400 >>> @@ -1089,7 +1089,14 @@ class _SubParsersAction(Action): >>> # parse all the remaining options into the namespace >>> # store any unrecognized options on the object, so that the top >>> # level parser can decide what to do with them >>> - namespace, arg_strings = parser.parse_known_args(arg_strings, >>> namespace) >>> + >>> + # In case this subparser defines new defaults, we parse them >>> + # in a new namespace object and then update the original >>> + # namespace for the relevant parts. >>> + subnamespace, arg_strings = parser.parse_known_args(arg_strings, >>> None) >>> + for key, value in vars(subnamespace).items(): >>> + setattr(namespace, key, value) >>> + >>> if arg_strings: >>> vars(namespace).setdefault(_UNRECOGNIZED_ARGS_ATTR, []) >>> getattr(namespace, _UNRECOGNIZED_ARGS_ATTR). >>> extend(arg_strings) >>> --- >>> >>> Which is related to http://bugs.python.org/issue9351 >>> >>> Maybe argparse just became more strict? I don't understand the issue. >>> >> >> Steven Bethard, the argparse maintainer, defined the old behavior of >> ignoring subparser defaults (where there are also top level defaults) as a >> bug "counter to what people probably expect". If the old behavior had been >> documented, changing it in a bug-fix release would have been a mistake. >> But looking at the patch, the doc seems to have been silent on the issue. >> >> This is not the first time someone considered a 'bug fix' to be a >> 'regression', which it might be from their viewpoint. The last comment on >> the github thread suggests that an easy fix was found. >> >> -- >> Terry Jan Reedy >> >> >> _______________________________________________ >> Python-Dev mailing list >> Python-Dev@python.org >> https://mail.python.org/mailman/listinfo/python-dev >> Unsubscribe: https://mail.python.org/mailman/options/python-dev/ >> guido%40python.org >> > > > > -- > --Guido van Rossum (python.org/~guido) > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/rymg19%40gmail.com > > -- Ryan If anybody ever asks me why I prefer C++ to C, my answer will be simple: "It's becauseslejfp23(@#Q*(E*EIdc-SEGFAULT. Wait, I don't think that was nul-terminated." Personal reality distortion fields are immune to contradictory evidence. - srean Check out my website: http://kirbyfan64.github.io/
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