def _expecting_arg_idx(arg, text):
    """Return the index of expecting argument.

    >>> _expecting_arg_idx("./da", ".import ./da")
    1
    >>> _expecting_arg_idx("./data.csv", ".import ./data.csv")
    1
    >>> _expecting_arg_idx("./data.csv", ".import ./data.csv ")
    2
    >>> _expecting_arg_idx("./data.csv t", ".import ./data.csv t")
    2
    """
    args = arg.split()
    return len(args) + int(text[-1].isspace())
