def flatten_dict(d: MutableMapping, parent_key: str = "", delimiter: str = "."):
    """Flatten a nested dict into a single level dict."""

    def _flatten_dict(d, parent_key="", delimiter="."):
        for k, v in d.items():
            key = str(parent_key) + delimiter + str(k) if parent_key else k
            if v and isinstance(v, MutableMapping):
                yield from flatten_dict(v, key, delimiter=delimiter).items()
            else:
                yield key, v

    return dict(_flatten_dict(d, parent_key, delimiter))
Flatten a nested dict into a single level dict.
dpkd/transformers/src/transformers/utils/generic.py