bpo-36602: Allow pathlib.Path.iterdir to list recursively

[EpicWink]

Currently, pathlib.Path.iterdir only lists contents of the instance directory. This enhancement allows iterdir to recurse into subdirectories.

The issue references two decisions to be made. I have initially chosen to not yield the contained directories themselves, and I have initially chosen to not resolve paths before checking if they're a directory to be recursed into. Don't hesitate to give criticism on these choices.

In addition, I've decided to make recursive a keyword-only argument, as path.iterdir(True) didn't seem very readable.

https://bugs.python.org/issue36602

[the-knights-who-say-ni]

Hello, and thanks for your contribution!

I'm a bot set up to make sure that the project can legally accept your contribution by verifying you have signed the PSF contributor agreement (CLA).

Unfortunately we couldn't find an account corresponding to your GitHub username on bugs.python.org (b.p.o) to verify you have signed the CLA (this might be simply due to a missing "GitHub Name" entry in your b.p.o account settings). This is necessary for legal reasons before we can look at your contribution. Please follow the steps outlined in the CPython devguide to rectify this issue.

You can check yourself to see if the CLA has been received.

Thanks again for your contribution, we look forward to reviewing it!

[bedevere-bot]

Thanks for making the requested changes!

: please review the changes made to this pull request.

[EpicWink]

#13153 has implemented the pathlib.Path API for zip-files. I would suspect an new request would be needed for updating zipfile with recursive directory listing as well

[EpicWink]

The introduction of pathlib.Path.walk, the existance of path.rglob("**"), and the simplicity of writing a helper function all contribute to my thinking this feature is not necessary. Feel free to close #80783.

PS: helper function:

def iterdir_recursive(path: pathlib.Path) -> typing.Generator[pathlib.Path, None, None]:
    for child in path.iterdir():
        if child.is_dir():
            yield from iterdir_recursive(child)
        else:
            yield child