I looked at the previewhttps://cpython-previews--124877.org.readthedocs.build/en/124877/library/argparse.html#module-argparse and skimmed the entire doc. Below are some things I noticed. None are new to this PR, so feel free to ignore them and I can file a separate PR with those cleanups.

• It's distracting that the first few paragraphs link:mod:`argparse` 4 times, and it just links back to the top of the page. Would recommend suppressing those links with:mod:`!argparse`.
• RawTextHelpFormatter description says "new lines"; I think it's normally spelled "newlines".
• "ArgumentParser usesfilesystem encoding and error handler to read the file containing arguments." this sentence reads oddly, maybe needs a "the"
• "the action default will not over write it" -> I think "overwrite" is one word
• I might remove theparser.add_argument('source_file', type=open) example. It doesn't make it easy to properly close the file, and as the text says later, FileNotFoundError would not be handled nicely.
• FileType is formatted inconsistently in the paragraph that startsEven [FileType](https://cpython-previews--124877.org.readthedocs.build/en/124877/library/argparse.html#argparse.FileType) has its limitations for use with the type keyword.
• The text after "class argparse.Action" should be indented by another level.
• The docs forparse_known_intermixed_args are not properly indented.

Thanks so much for such a thorough review,@JelleZijlstra. I think I can incorporate your feedback in this PR. I'll revisit this tomorrow evening.

@JelleZijlstra, I applied all of your suggestions. I also found formatting inconsistencies in taking another pass related to indentation and style.

Thanks@savannahostrowski for the PR, and@JelleZijlstra for merging it 🌮🎉.. I'm working now to backport this PR to: 3.12, 3.13.
🐍🍒⛏🤖

Sorry,@savannahostrowski and@JelleZijlstra, I could not cleanly backport this to3.13 due to a conflict.
Please backport usingcherry_picker on command line.

cherry_picker 37228bd16e3ef97d32da08848552f7ef016d68ab 3.13

Sorry,@savannahostrowski and@JelleZijlstra, I could not cleanly backport this to3.12 due to a conflict.
Please backport usingcherry_picker on command line.

cherry_picker 37228bd16e3ef97d32da08848552f7ef016d68ab 3.12

GH-125162 is a backport of this pull request to the3.13 branch.

GH-125164 is a backport of this pull request to the3.12 branch.