code: def _read_precursor(precursor, sps):
      
      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
docs: Load precursor file for that species