python2.7语法, py3请自行相应改下

import glob
import os
src_dir = '/root/*.txt'      # 利用通配符查找后缀名为txt的文件
dest_file = 'result.txt'
with open(dest_file, 'w') as f_w:
    for file_name in glob.glob(src_dir):
        with open(file_name) as f_r:
            for line in f_r:
                f_w.write('%s %s' % (file_name, line))
        os.remove(file_name)