from typing import Any, Union


def format_for_dataloader(
    items: list[dict[str, Any]],
    keys: list[Any],
    lookup_key: str,
) -> list[Union[dict[str, Any] | None]]:
    """Transforms a list of items to be a dataloader-formatted list of items.

    Items will be ordered by the keys provided.
    Where no item is found for the key, None is used for the item.
    """
    items_dict = {str(item[lookup_key]): item for item in items}
    return [items_dict.get(str(key), None) for key in keys]