code: def filter(fastq, sam, paired = False):
  	
  	if paired is False:
  		list = sam_list(sam)
  	else:
  		list = sam_list_paired(sam)
  	if paired is False:
  		filter_fastq(fastq, list)
  	else:
  		filter_fastq_paired(fastq, list)
docs: filter sequences that are shown to be mapped in the sam file
  	reads not in sam file are in *.filtered.fastq
  	reads that are in the sam file are in *.matched.fastq