def _read_precursor(precursor, sps):
    """
    Load precursor file for that species
    """
    hairpin = defaultdict(str)
    name = None
    with open(precursor) as in_handle:
        for line in in_handle:
            if line.startswith(">"):
                if hairpin[name]:
                    hairpin[name] = hairpin[name] + "NNNNNNNNNNNN"
                name = line.strip().replace(">", " ").split()[0]
            else:
                hairpin[name] += line.strip()
        hairpin[name] = hairpin[name] + "NNNNNNNNNNNN"
    return hairpin
Load precursor file for that species