code: def trim(args):
      
      p = OptionParser(trim.__doc__)
      p.add_option("-f", dest="first", default=0, type="int",
              help="First base to keep. Default is 1.")
      p.add_option("-l", dest="last", default=0, type="int",
              help="Last base to keep. Default is entire read.")
      opts, args = p.parse_args(args)
  
      if len(args) != 1:
          sys.exit(not p.print_help())
  
      fastqfile, = args
      obfastqfile = op.basename(fastqfile)
      fq = obfastqfile.rsplit(".", 1)[0] + ".ntrimmed.fastq"
      if fastqfile.endswith(".gz"):
          fq = obfastqfile.rsplit(".", 2)[0] + ".ntrimmed.fastq.gz"
  
      cmd = "fastx_trimmer -Q33 "
      if opts.first:
          cmd += "-f {0.first} ".format(opts)
      if opts.last:
          cmd += "-l {0.last} ".format(opts)
  
      sh(cmd, infile=fastqfile, outfile=fq)
docs: %prog trim fastqfile
  
      Wraps `fastx_trimmer` to trim from begin or end of reads.