code: def blast(args):
      
      p = OptionParser(blast.__doc__)
      opts, args = p.parse_args(args)
  
      if len(args) != 1:
          sys.exit(not p.print_help())
  
      deltafile, = args
      blastfile = deltafile.rsplit(".", 1)[0] + ".blast"
  
      if need_update(deltafile, blastfile):
          coords = Coords(deltafile)
          fw = open(blastfile, "w")
          for c in coords:
              print(c.blastline, file=fw)
docs: %prog blast <deltafile|coordsfile>
  
      Covert delta or coordsfile to BLAST tabular output.