def make_branch_indices(branch_ids, dc=False):
    """Make the indices of existing branch for input to Switch.

    :param iterable branch_ids: list of original branch ids.
    :param bool dc: branch_ids are for dclines or not, defaults to False.
    :return: (*list*) -- list of branch indices for input to Switch
    """
    return [f"{i}dc" if dc else f"{i}ac" for i in branch_ids]