code: def generate_psms_split(fn, oldheader, bioset, splitcol):
      
      try:
          splitcolnr = get_splitcolnr(oldheader, bioset, splitcol)
      except IndexError:
          raise RuntimeError('Cannot find bioset header column in '
                             'input file {}, though --bioset has '
                             'been passed'.format(fn))
      for psm in tsvreader.generate_tsv_psms(fn, oldheader):
          yield {'psm': psm,
                 'split_pool': psm[oldheader[splitcolnr]]
                 }
docs: Loops PSMs and outputs dictionaries passed to writer. Dictionaries
      contain the PSMs and info to which split pool the
      respective PSM belongs