def read_blacklist_file(blacklist_file_path):
    """
    Input is path to blacklist file. Blacklist file can be either
    structured as <taxonID>\t<any other stuff, i.e. lineage...>
    or just as <taxonID>.

    This function returns a set of taxonIDs that are in the blacklist
    """
    blacklist = set()
    with open(blacklist_file_path, 'r') as infile:
        for line in infile:
            if len(line.split('\t')) >1:
                line = line.split('\t')
                taxonID = line[0]
                blacklist.add(int(taxonID))
            else:
                taxonID = line.rstrip('\n')
                blacklist.add(int(taxonID))

    return blacklist