argparse: disable abbreviation

[jensjaehrig]

BPO	14910
Nosy	@ericvsmith, @bitdancer, @berkerpeksag, @remram44
Files	disable-abbrev.patch: Patch wi/tests,doc 14910.patch issue14910_2.patch issue_14910_3.diff issue14910_4.diff issue14910_5.diff issue14910_6.diff issue14910_7.diff.txt

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/berkerpeksag'
closed_at = <Date 2015-02-13.23:41:44.333>
created_at = <Date 2012-05-25.10:59:55.919>
labels = ['type-feature', 'library']
title = 'argparse: disable abbreviation'
updated_at = <Date 2015-02-13.23:41:44.332>
user = 'https://bugs.python.org/jensjaehrig'

bugs.python.org fields:

activity = <Date 2015-02-13.23:41:44.332>
actor = 'berker.peksag'
assignee = 'berker.peksag'
closed = True
closed_date = <Date 2015-02-13.23:41:44.333>
closer = 'berker.peksag'
components = ['Library (Lib)']
creation = <Date 2012-05-25.10:59:55.919>
creator = 'jens.jaehrig'
dependencies = []
files = ['25729', '26481', '35191', '36207', '36228', '36229', '36246', '36260']
hgrepos = []
issue_num = 14910
keywords = ['patch']
message_count = 24.0
messages = ['161566', '161672', '161680', '166160', '166161', '166162', '187235', '204678', '218137', '224557', '224567', '224616', '224617', '224629', '224654', '224699', '224775', '225009', '234476', '234477', '235362', '235421', '235926', '235928']
nosy_count = 15.0
nosy_names = ['bethard', 'eric.smith', 'r.david.murray', 'eli.bendersky', 'daniel.ugra', 'tshepang', 'python-dev', 'berker.peksag', 'paul.j3', 'jens.jaehrig', 'jpaugh', 'puppet', 'Michael.Edwards', 'remram', 'xobes']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue14910'
versions = ['Python 3.5']

[jensjaehrig]

argparse uses per default abbreviation in unambiguous cases.

I don't want abbreviation and i'd like to disable it.
But theres no option to do this.
http://docs.python.org/library/argparse.html#argument-abbreviations
Only to override the Handler like suggested here: http://stackoverflow.com/questions/10750802/python-argparse-disable-abbreviation/10751356#10751356

################
# Example #
################

    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('--send', action='store_true')
    parser.parse_args(['--se']) # returns Namespace(send=True)

But i want it only to be true when the full parameter is supplied. To prevent user errors.

[jpaugh]

I am dubious as to the use of this: I think resolving partial args is one of the best thing since invented since sliced bread.

However, it's a good project to get my feet wet, so I'll take it on. I should have a patch later today--I'm working on test-cases just now.

[jpaugh]

I created a patch that exibhts the requested behavior. I added tests, and updated the documentation. I ran the test-suite against a build of Python 3.3.0a3+, and all tests check out.

This changes the public API of argparse.ArgumentParser and of its parse_args() method.

[bethard]

I think it makes a lot of sense to allow people to disable abbreviations, so +1 on the feature request.

The patch looked good. There was one typo - using "accept_abbrev" in the docstring instead of "allow_abbrev" as in the implementation, and I fixed that and uploaded a new patch.

To be complete, the patch also needs to add some documentation, edit Misc/NEWS, etc. See:

http://docs.python.org/devguide/patch.html#preparation

[bethard]

Sorry, my mistake, the doc changes were already in the patch. I just checked them and they look good too. So everything's ready to commit.

Thanks for your contribution!

[bitdancer]

Jonathan: we are in feature freeze right now preparing 3.3 for release, so you might want to ping the issue once 3.3 is out to remind us to do the checkin.

[BreamoreBoy]

Ping :)

[paulj3]

For a programmer who needs to turn off this abbreviation matching now, a simple solution is to subclass ArgumentParser:

    class MyParser(ArgumentParser):
        def _get_option_tuples(self, option_string):
            return []

This could be the place to implement more specialized matching (e.g. do not match on strings like '--sync').

[paulj3]

Update the patch -
test_argparse.py - cleanup spaces
argparse.rst - merging conflicts

[puppet]

Update the patch - issue_14910_3.diff
argparse.rst - merging conflicts

[elibendersky]

Daniel, I left some comments in Rietveld. Also it doesn't seem that you addressed the previously left comments when you fixed up the patch.

[puppet]

Oh, completely missed comments there too!

I hope I got them all in a good way!

[puppet]

Sorry for a new patch this close, but just tripple checked the documentation and noticed a word to much. Made it more clear hopefully

[elibendersky]

No worries, Daniel. You should have received an email when comments were posted to the review, did you? If you you may want to check your settings in the bug tracker.

I left a couple of additional comments on the documentation file, but other than that this LGTM.

[puppet]

Eli, will look into those tomorrow morning, so a final patch will come during tomorrow. Checked my spam folder - and there they where, fixed the settings now so I get it faster.

[puppet]

Fixed documentation issues

[puppet]

Updated patch

[elibendersky]

Ezio, could you see if your comments were addressed?

Steven, do you want to take another look, or is this OK to commit?

[xobes]

This breaks custom actions.

e.g.:

class dict_action(argparse.Action):
    def __init__(self, *a, **k):
        argparse.Action.__init__(self, *a, **k)

TypeError: __init__() got an unexpected keyword argument 'allow_abbrev'

[xobes]

Ignore previous comment, I wish I could delete it.

I simply provided the allow_abbrev to the wrong function and spent zero time investigating the error.

[remram44]

It looks like the previous comments were addressed in the latest patch. Is this still planned for 3.5? Alpha 1 is next week according to PEP-478.

[berkerpeksag]

The patch LGTM.

In Doc/library/argparse.rst:

•                      add_help=True)
  

+ allow_abbrev=True, add_help=True)

should be

    add_help=True, allow_abbrev=True)

I'll add a release note and commit it. Thanks!

[python-dev]

New changeset 99302634d756 by Berker Peksag in branch 'default':
Issue bpo-14910: Add allow_abbrev parameter to argparse.ArgumentParser.
https://hg.python.org/cpython/rev/99302634d756

[berkerpeksag]

Committed. Thank you all for patches and reviews :)