def compute_min_alignment_length(seqs_f, fraction=0.75):
 med_length = median([len(s) for (_, s) in parse_fasta(seqs_f)])
 return int((med_length * fraction))

def compute_min_alignment_length ( seqs_f , fraction = 0.75 ) : med_length = median ( [ len ( s ) for ( _ , s ) in parse_fasta ( seqs_f ) ] ) return int ( ( med_length * fraction ) )
compute the min alignment length as n standard deviations below the mean .