python遍历文件及其替换文件内容

[root@localhost python]# cat modify_db.py
#!/usr/bin/python
import os
dir ='/data/script/shell/bak3303_201308011221'
dir2='/data/script/python/out_db/'
files=os.listdir(dir)
for f in files:
    print f
    file1=os.path.join(dir,f)
    file_object=open(file1,'r')
    all_the_txt=file_object.read()
    file2=all_the_txt.replace('DEFINER=`root`@`%`','')
    file_object2=os.path.join(dir2,f)
    file_object3=open(file_object2,'w')
    file_object3.write(file2)
    file_object.close()
    file_object3.close()

遍历dir文件夹下的内容，进行DEFINER=`root`@`%`替换成空格，最后按原文件名保存到dir2文件夹下。