python：for & if 获取两个文本的差集、交集

方法：
1 一个文本用readlines()读成列表，当作库
2 for遍历另一个文本，if判断各元素是否在库
3 不在则是差集，在则是交集

readlines()读取含换行符，因此for遍历则不必strip()，等价匹配

示例：

#!/usr/bin/env python3
import re, os, sys
with open("cgr2.total.uniq2uhgg", 'w') as o:
    with open("uhgg.total.uniq", 'r') as db:
        db = db.readlines()
        with open("cgr2.total.uniq", 'r') as f:
            for line in f:
                if line not in db:
                    o.write("{}".format(line))

#!/usr/bin/env python3
import re,os,sys
with open("prokka_error.tsv_left", 'w') as o:
    with open("prokka_error_6.tsv", 'r') as db:
        db = db.readlines()
        with open("prokka_error.tsv", 'r') as f:
            for line in f:
                if line not in db:
                    o.write("{}".format(line))