def _fmt_path(path):
    """Format the path for final display.

    Parameters
    ----------
    path : iterable of str
        The path to the values that are not equal.

    Returns
    -------
    fmtd : str
        The formatted path to put into the error message.
    """
    if not path:
        return ''
    return 'path: _' + ''.join(path)