Confusing error message when options for `python` are erroneously quoted

Bug report

Bug description:

#!/bin/python -q -i

I was writing an unrelated post about shebang lines tricks+tips, and happened to pick python as an example, only to discover some weird behavior. The above gets parsed as /bin/python "-q -i" <path/to/script>

But the message python prints is quite confusing:

Unknown option: - 
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

What's happening is that the "unknown option" is a single space, being parsed as a short-form option, and printed. But the output is pretty opaque, since the space is not quoted, and it's just a trailing invisible space.

Aside: Several other invalid one-byte options like \n get printed wrongly. This doesn't seem worth fixing.

Proposed fix:

I think the shebang case happens to users often enough that it would be good to have some kind of better error message if a short-form options list contains either of

• - (this would require scanning ahead!), which either indicates some quoting problem, or an incorrect long-form option (-check-hash-based-pycs rather than --check-hash-based-pycs).

I think a good error message could be unknown option: -q -i or unknown option: "-q -i". Quoting the argument when it contains a space seems clearer to me.

The current long-form options have pretty clear error messages either way, mostly by happenstance.

Currently, -help-* parses as -h which then prints help, stopping option parsing. I have no strong opinion about whether that behavior is better or worse than printing an error message.

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Reproduisez l’invocation shebang signalée /bin/python -q -i et examinez l’analyse des options de ligne de commande de CPython ainsi que les points d’entrée du signalement des erreurs. Concentrez-vous sur la manière dont une chaîne d’options entre guillemets devient une option courte, puis vérifiez que le diagnostic qui en résulte identifie visiblement l’argument invalide sans modifier le comportement d’options invalides d’un octet sans rapport.