Restore all objects under S3 prefix in versioned bucket

restore.py

# Restores all objects under a prefix in an S3 bucket to the version they were before being deleted.
# Works by deleting the latest delete marker for the objects.
import boto3

bucket = 'the-bucket'
prefix = 'the-prefix/'
region = 'eu-west-2'

client = boto3.client('s3', region_name=region)
paginator = client.get_paginator('list_object_versions')
page_iterator = paginator.paginate(
    Bucket=bucket,
    Prefix=prefix,
)
latest_delete_markers = (
    dm
    for page in page_iterator
    for dm in page['DeleteMarkers']
    if dm['IsLatest']
)

for dm in latest_delete_markers:
    client.delete_object(
        Bucket=bucket,
        Key=dm['Key'],
        VersionId=dm['VersionId'],
    )