Python: search for a nested key in a dictionary but do not throw errors if the key does not exists (kinda like the ?? operator)

key_in_dict.py

def key_in_dict(_dict: dict, key_lookup: str, separator='.'):
    """
        Searches for a nested key in a dictionary and returns its value, or None if nothing was found.
        key_lookup must be a string where each key is deparated by a given "separator" character, which by default is a dot
    """
    if not isinstance(_dict, dict):
        raise TypeError('First argument must be type Dict')

    keys = key_lookup.split(separator)
    subdict = _dict

    for k in keys:
        subdict = subdict[k] if (isinstance(subdict, dict) and k in subdict) else None

        if subdict is None: break

    return subdict