[`argparse`] `action='store_true'` and `action='store_false'` are affected by `argument_default`

Documentation

While the docs seem to imply that False and True are always the defaults for the store_true and store_false actions respectively, that is only true if argument_default is not passed. This should be more clearly documented.

>>> import argparse
>>> parser = argparse.ArgumentParser(prog='baz', argument_default=argparse.SUPPRESS)
>>> parser.add_argument('-s', '--spam', action='store_true')
_StoreTrueAction(option_strings=['-s', '--spam'], dest='spam', nargs=0, const=True, default='==SUPPRESS==', type=None, choices=None, required=False, help=None, metavar=None, deprecated=False)
>>> parser.parse_args()
Namespace()
>>> parser.parse_args(['-s'])
Namespace(spam=True)

Linked PRs

• gh-155404

从 issue 中链接的 argparse action 文档开始，将其中对 store_true/store_false 的措辞与所示的 argument_default 示例进行比较。完成的标准是文档明确描述它们之间的交互，并保留所演示的行为；PR gh-155404 已经链接。