[FEATURE] A function similar to s3 ls

[aamster]

Summary

I needed a function that is similar to ls to just list paths at a given S3URI.

Justification

list_s3_paths is recursive and only lists files, not directories, for example, as ls would.

Solution

I implemented this function for aibs-informatics-AD-image-convert library:

def list_directories(s3_path: S3URI, **kwargs):
    s3_client = get_s3_client(**kwargs)
    paginator = s3_client.get_paginator("list_objects_v2")

    operation_parameters = {
        "Bucket": s3_path.bucket,
        "Delimiter": "/",
        "Prefix": s3_path.key,
    }

    page_iterator = paginator.paginate(**operation_parameters)

    directories = []

    for page in page_iterator:
        if "CommonPrefixes" in page:
            for common_prefix in page["CommonPrefixes"]:
                directories.append(common_prefix["Prefix"])

    return directories

If this is implemented, that function should be replaced with this new one.