统计CDS中的密码子数目

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-
    __author__ = "Sheng-Wei Ma"
    
    from Bio import SeqIO
    from collections import OrderedDict
    
    records = (r for r in SeqIO.parse('cds.fa', "fasta"))
    count_file = open('cds.count.txt', 'w')
    fre_file = open('cds.frequency.txt', 'w')
    
    count_file.writelines('%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t