code: def gene_one_per_line(in_file, data):
      
      if in_file:
          # Report all duplicated annotations one-per-line
          one_per_line_file = "%s-opl.bed" % utils.splitext_plus(in_file)[0]
          if not utils.file_uptodate(one_per_line_file, in_file):
              with file_transaction(data, one_per_line_file) as tx_out_file:
                  with open(tx_out_file, 'w') as out:
                      for r in pybedtools.BedTool(in_file):
                          for g in r.name.split(','):
                              out.write('\t'.join(map(str, [r.chrom, r.start, r.end, g])) + '\n')
          return one_per_line_file
docs: Split comma-separated gene annotations (after add_genes). Leads to duplicated records.
         Input:
            chr1 100 200 F1,F2
         Output:
            chr1 100 200 F1
            chr1 100 200 F2