code: def gaps(args):
      
      p = OptionParser(gaps.__doc__)
      opts, args = p.parse_args(args)
  
      if len(args) != 1:
          sys.exit(not p.print_help())
  
      blastfile, = args
      blast = BlastSlow(blastfile)
      logging.debug("A total of {} records imported".format(len(blast)))
  
      query_gaps = list(collect_gaps(blast))
      subject_gaps = list(collect_gaps(blast, use_subject=True))
      logging.debug("Query gaps: {}  Subject gaps: {}"\
                      .format(len(query_gaps), len(subject_gaps)))
  
      from jcvi.graphics.base import savefig
      import seaborn as sns
  
      sns.distplot(query_gaps)
      savefig("query_gaps.pdf")
docs: %prog gaps A_vs_B.blast
  
      Find distribution of gap sizes betwen adjacent HSPs.