recursve merging of dictionaries

merge_dicts.py

def merge_dicts(a: dict, b: dict, path: List[str] = [], update: bool = True) -> dict:
    """
    Merge two dictionaries recursively.

    :param a: The first dictionary.
    :param b: The second dictionary.
    :param path: The path to the current key.
    :param update: If True, the value in dictionary 'b' will replace that in 'a' on conflict,
        otherwise an exception will be raised.
    """
    for key in b:
        if key in a:
            if isinstance(a[key], dict) and isinstance(b[key], dict):
                merge_dicts(a[key], b[key], path + [str(key)])
            elif a[key] != b[key]:
                if update:
                    a[key] = b[key]
                else:
                    raise Exception("Conflict at " + ".".join(path + [str(key)]))
        else:
            a[key] = b[key]
    return a