code: def _read_gtf(gtf):
      
      if not gtf:
          return gtf
      db = defaultdict(list)
      with open(gtf) as in_handle:
          for line in in_handle:
              if line.startswith("#"):
                  continue
              cols = line.strip().split("\t")
              name = [n.split("=")[1] for n in cols[-1].split(";") if n.startswith("Name")]
              chrom, start, end, strand = cols[0], cols[3], cols[4], cols[6]
              if cols[2] == "miRNA_primary_transcript":
                  db[name[0]].append([chrom, int(start), int(end), strand])
      return db
docs: Load GTF file with precursor positions on genome