[issue41592] Make _SubParsersAction public

[Eric Pederson]

New submission from Eric Pederson <ericacm at gmail.com>:

ArgumentParser.add_subparsers() returns a _SubParsersAction.  This requires user code using type annotations to use a protected type which causes type checkers like PyCharm to complain.  For example:

def add_subparser(name: str, subparser: _SubParsersAction, subparsers: dict) -> ArgumentParser:
    parser = subparser.add_parser(name)
    parser.add_argument('-v', '--verbose', action='store_true')
    subparsers[name] = parser
    return parser

You can't use plain Action because Action doesn't have the add_parser() method.

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components: Library (Lib)
messages: 375670
nosy: sourcedelica
priority: normal
severity: normal
status: open
title: Make _SubParsersAction public
type: enhancement
versions: Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41592>
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