经常遇到提取问题，一旦要提取的文件很大，关键字很多，可以使用集合

#!/usr/bin/env python
# -*- coding: utf-8 -*- 
__author__ = 'Shengwei Ma'
__author_email__ = 'shengweima@icloud.com'


with open('3.txt', 'r') as f1:
    a = set(line.strip() for line in f1)

with open('wheat_est_gi.fa.gff3', 'r') as f:
    for line in f:
        line1 = line.strip().split('\t')
        Name = line1[8].split(';')[1].split('=')[1]
        if Name in a:
            print line,