S3 batch delete

[kislyuk]

bucket = s3.Bucket(...)
def delete_objects(objs):
    print(len(objs), objs[0])
    return bucket.delete_objects(Delete={"Objects": [{"Key": obj.key} for obj in objs]})
with ThreadPoolExecutor(max_workers=4) as executor:
    for res in executor.map(delete_objects, batched(bucket.objects.all(), 1000)):
        print(json.dumps(res))