from typing import Any, Dict, Iterable, Union


def flatten(
    d: Union[Dict[str, Any], Dict[int, Any]], parent: str = "", sep: str = "."
) -> Dict[Union[str, int], Any]:
    """
    Flatten dictionary keys.
    """
    ret = {}
    for key, value in d.items():
        new_key = str(sep.join([str(parent), str(key)]) if parent else key)
        if isinstance(value, dict):
            ret.update(flatten(value, new_key, sep=sep))
        else:
            ret[new_key] = value
    return ret


def exclude(d: Dict[str, Any], *, keys: Iterable[str]) -> Dict[str, Any]:
    return {i: d[i] for i in d if i not in keys}