saltstack文件模块的replace操作简化

代码已经过测试

import re
import mmap
import os
import shutil

old_text='test'
new_text='text'
path=r'C:\Users\Administrator\Desktop\2.txt'
cpattern = re.compile(str(old_text))

with open(path,mode='rb') as r_file:
    try:
        # mmap throws a ValueError if the file is empty.
        r_data = mmap.mmap(r_file.fileno(),
                           0,
                           access=mmap.ACCESS_READ)
    except (ValueError, mmap.error):
        # size of file in /proc is 0, but contains data
        r_data = "".join(r_file)
    result= re.sub(cpattern, new_text, r_data)
    r_data.close()

with open(path,mode='w') as w_file:
    w_file.write(result)