def index2taxid(label_file):
    """Turns the label info into a dict={label: taxid}."""
    lab_dic = {}
    with open(label_file) as handle:
        for line in handle:
            line_ls = line.rstrip().split('\t')
            label_id = int(line_ls[0])
            taxon_id = int(line_ls[1])
            lab_dic[label_id] = taxon_id
    return lab_dic