def METHOD_NAME(args):
    r1_out_path = args.output_file_prefix + '_1.fastq'
    r2_out_path = args.output_file_prefix + '_2.fastq'
    filesnpaths.is_output_file_writable(r1_out_path, ok_if_exists=False)
    filesnpaths.is_output_file_writable(r2_out_path, ok_if_exists=False)
    r1_out = open(r1_out_path, 'w')
    r2_out = open(r2_out_path, 'w')
    fastq = FastqParse(args.fastq)
    progress.new('Processing reads', progress_total_items=fastq.num_reads)
    for i, read in enumerate(fastq.loop_reads()):
        if i % 100000 == 0:
            progress.increment(i)
            progress.update('%d / %d' % (i, fastq.num_reads))
        read1_len = len(read.seq)//2
        read1_seq = read.seq[:read1_len]
        read1_qual = read.qual[:read1_len]
        read2_seq = utils.rev_comp(read.seq[read1_len:])
        read2_qual = read.qual[read1_len:][::-1]
        r1_out.write('\n'.join([
            read.id1,
            read1_seq,
            read.id2,
            read1_qual,
        ]) + '\n')
        r2_out.write('\n'.join([
            read.id1,
            read2_seq,
            read.id2,
            read2_qual,
        ]) + '\n')
    r1_out.close()
    r2_out.close()
    progress.end()
    run.info_single("Done!")