Replace the old `getopt` with `argparse` in pdb CLI

[gaogaotiantian]

Feature or enhancement

Proposal:

pdb is using getopt for argument parsing. getopt is pretty old and not well maintained. Some issue in #108791 could be avoided with the modern argparse module. We should replace getopt with argparse when it's easy to do so. This might ease the load in the future when more arguments are added to the CLI.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-109164: Replace getopt with argparse in pdb #109165

[serhiy-storchaka]

Actually, getopt is stable and argparse has many bugs (some of them are design flaws).

[ericvsmith]

I agree that argparse has many problems and isn't the best choice. And this is coming from someone who was pushing to get it in the stdlib.

[gaogaotiantian]

getopt is soft deprecated since 3.13. It doesn't mean that we can't use it, it's just we should try to use actively maintained stdlib. Also the CLI for pdb is not that complicated. I agree there are issues with argparse, but there are issues with getopt as well (see the linked issue). I believe CPython will always have a CLI parser in its stdlib. It's argparse now but maybe in the future there will be a better designed alternative, we can switch to that then.