code: def gb(args):
      
      from Bio.Alphabet import generic_dna
      try:
          from BCBio import GFF
      except ImportError:
          print("You need to install dep first: $ easy_install bcbio-gff", file=sys.stderr)
  
      p = OptionParser(gb.__doc__)
      opts, args = p.parse_args(args)
  
      if len(args) != 2:
          sys.exit(not p.print_help())
  
      gff_file, fasta_file = args
      pf = op.splitext(gff_file)[0]
      out_file = pf + ".gb"
      fasta_input = SeqIO.to_dict(SeqIO.parse(fasta_file, "fasta", generic_dna))
      gff_iter = GFF.parse(gff_file, fasta_input)
      SeqIO.write(gff_iter, out_file, "genbank")
docs: %prog gb gffile fastafile
  
      Convert GFF3 to Genbank format. Recipe taken from:
      <http://www.biostars.org/p/2492/>