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argparse: subparsers, argument abbreviations and ambiguous option #58573

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argparse: subparsers, argument abbreviations and ambiguous option#58573
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serhiy-storchaka
Labels
3.12only security fixes3.13only security fixes3.14bugs and security fixesstdlibStandard Library Python modules in the Lib/ directorytype-bugAn unexpected behavior, bug, or error

Description

@jakub
jakub
mannequin
opened on Mar 18, 2012
BPO 14365
Nosy @merwok
Files
  • argparse_subparsers_ambiguous_bug.py: Bug reproduction
  • argparse_dirty_hack.py
  • subparser_optionals.diff
  • subparser_patch.diff
    		•

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

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    GitHub fields:

    assignee = None
closed_at = None
created_at = <Date 2012-03-18.20:27:59.700>
labels = ['type-bug', 'library']
title = 'argparse: subparsers, argument abbreviations and ambiguous option'
updated_at = <Date 2014-08-07.22:47:31.748>
user = 'https://bugs.python.org/jakub'

    bugs.python.org fields:

    activity = <Date 2014-08-07.22:47:31.748>
actor = 'paul.j3'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2012-03-18.20:27:59.700>
creator = 'jakub'
dependencies = []
files = ['24928', '24945', '26466', '31901']
hgrepos = []
issue_num = 14365
keywords = ['patch']
message_count = 14.0
messages = ['156272', '156279', '156280', '156290', '156302', '156304', '156306', '156352', '166059', '198456', '198507', '198508', '198563', '225044']
nosy_count = 5.0
nosy_names = ['bethard', 'eric.araujo', 'tshepang', 'paul.j3', 'jakub']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'test needed'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue14365'
versions = ['Python 2.7', 'Python 3.2', 'Python 3.3']

    Linked PRs

    Activity

    1. jakub commented on Mar 18, 2012

      @jakub
      jakubmannequin
      on Mar 18, 2012
      MannequinAuthor

      Assuming following:

      1. optional argument, say "--foo", in a subparser;
      2. at least two different optional arguments in the main parser prefixed with "--foo", say "--foo1" and "--foo2";

      parsing fails with "error: ambiguous option: --foo could match --foo1, --foo2".

      It seems like argument abbreviation mechanism described at http://docs.python.org/library/argparse.html#argument-abbreviations is not working properly when in use with subparsers...

    2. jakub
      added
      stdlibStandard Library Python modules in the Lib/ directory
      type-bugAn unexpected behavior, bug, or error
      on Mar 18, 2012

    3. tshepang commented on Mar 18, 2012

      @tshepang
      tshepangmannequin
      on Mar 18, 2012
      Mannequin

      More or less a duplicate of 12713?

    4. tshepang commented on Mar 18, 2012

      @tshepang
      tshepangmannequin
      on Mar 18, 2012
      Mannequin

      Sorry, I meant bpo-12713.

    5. bethard commented on Mar 18, 2012

      @bethard
      bethardmannequin
      on Mar 18, 2012
      Mannequin

      Yep. Closing as duplicate.

    6. bethard
      closed this as completedon Mar 18, 2012

    7. jakub commented on Mar 19, 2012

      @jakub
      jakubmannequin
      on Mar 19, 2012
      MannequinAuthor

      I don't understand how both bugs are related. Surely, patch provided for bpo-12713 does not fix the issue I described.

    8. bethard commented on Mar 19, 2012

      @bethard
      bethardmannequin
      on Mar 19, 2012
      Mannequin

      My mistake. I see that the error you're getting is a bad interaction between the option in the main parser and an ambiguous option in the subparser.

    9. bethard
      reopened this on Mar 19, 2012

    10. bethard commented on Mar 19, 2012

      @bethard
      bethardmannequin
      on Mar 19, 2012
      Mannequin

      The problem is basically that _parse_known_args calls _parse_optional to determine whether something is an optional or a positional. But _parse_optional only checks "if arg_string in self._option_string_actions", that is, if the string can be found in the main parser actions.

      So either this method needs to check the subparser actions, or the "if arg_string in self._option_string_actions" stuff needs to be delayed until the subparser. Neither of these seems like a simple change, but I agree it's a bug.

    11. jakub commented on Mar 19, 2012

      @jakub
      jakubmannequin
      on Mar 19, 2012
      MannequinAuthor

      Attached quick&dirty fix I'm currently using in my project. Maybe this will help to create a valid patch.

      Instead of changing _parse_optional, I've overridden _get_option_tuples to scan subparsers for matching optional arguments if option is ambiguous in the current parser.

      I've only skimmed through the code, so forgive me if that fix is useless.

    12. bethard commented on Jul 21, 2012

      @bethard
      bethardmannequin
      on Jul 21, 2012
      Mannequin

      I think the real fix needs to search recursively though all subparsers. Here's a first draft of a patch that does this. I believe your sample code works after this patch.

      I don't have the time to turn your bug report into proper test (and add a test for the recursive bit), but hopefully this is enough to let someone else finish up fixing this bug.

      And yes, your "dirty hack" was still helpful in putting this together. ;-)

    13. paulj3 commented on Sep 26, 2013

      @paulj3
      paulj3mannequin
      on Sep 26, 2013
      Mannequin

      Steven's patch (subparse_optionals.diff) run with jakub's test case (argparse_subparses_ambiguous_bug.py) works. But if the input string is

          print(parser.parse_args('--foo baz'.split()))

      produces

          Namespace(cmd=None, foo='baz', foo1=None, foo2=None)

      (I added the 'cmd' subparse 'dest').

      Two things seem to be going on now:

      1. '--foo' is being parsed even though its subparser is not invoked,

      2. and the subparser is not required.

      The issue of whether subparsers are required or not is another issue. They used to be required, but the testing for 'required' was changed, and subparsers fell through the crack.

      I suspect that if the missing subparser error were raised, the first issue wouldn't be apparent.

    14. paulj3 commented on Sep 28, 2013

      @paulj3
      paulj3mannequin
      on Sep 28, 2013
      Mannequin

      I think the correction to the problem that I noted in the previous post is to return 'None, arg_string, None', rather than 'action, arg_string, None' in the case where the action is found in a subparser.

      This is what '_parse_optional' does at the end:

              # it was meant to be an optional but there is no such option
        # in this parser (though it might be a valid option in a subparser)
        return None, arg_string, None

      An input like '--foo baz' would then produce an 'invalid choice' error. Since '--foo' is an optional that the primary parser does not recognize, 'baz' in interpreted as a positional, in this case an invalid subparser choice.

      I'm working on cleaning up a test script.

    15. 18 remaining items

    16. serhiy-storchaka
      added a commit that references this issue on Sep 29, 2024

      [3.12] gh-58573: Fix conflicts between abbreviated long options in th…

      cbea45a
    17. serhiy-storchaka
      closed this as completedon Sep 29, 2024
    18. github-project-automation
      moved this from Bugs to Doc issues in Argparse issueson Sep 29, 2024
    19. AdamWill
      added 3 commits that reference this issue on Oct 2, 2024

      options: adjust to behavior change in upstream _parse_optional

      8c5afb9

      options: adjust to behavior change in upstream _parse_optional

      b64e926

      options: adjust to behavior change in upstream _parse_optional

      7b9ddb1
    20. bcl
      added 2 commits that reference this issue on Oct 2, 2024

      options: adjust to behavior change in upstream _parse_optional

      f753d4d

      options: adjust to behavior change in upstream _parse_optional

      06eafb7
    21. serhiy-storchaka
      added 3 commits that reference this issue on Oct 7, 2024

      [3.13] gh-58573: Fix conflicts between abbreviated long options in th…

      6925e5b

      pythongh-125254: Fix error report about ambiguous option in argparse

      d4009a2

      gh-125254: Fix error report about ambiguous option in argparse (GH-12…

      63cf4e9
    22. miss-islington
      added 2 commits that reference this issue on Oct 12, 2024

      pythongh-125254: Fix error report about ambiguous option in argparse (p…

      5db7fd9

      pythongh-125254: Fix error report about ambiguous option in argparse (p…

      8998491
    23. serhiy-storchaka
      added 2 commits that reference this issue on Oct 12, 2024

      [3.12] gh-125254: Fix error report about ambiguous option in argparse (…

      aa0cdeb

      [3.13] gh-125254: Fix error report about ambiguous option in argparse (…

      33c4136
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