python过滤log数据并输出到txt文件

import re
import sys
import csv #好像没用，忘了
import os

fileDir = "C:/Users/Administrator/Desktop/过滤数据/log_orig/"
fileDirN = "C:/Users/Administrator/Desktop/过滤数据/cpu/"

output=sys.stdout
for file in os.listdir(fileDir):
    
    with open(fileDir+file,'r',encoding='UTF-8',errors='ignore') as f:
        fileName = re.split('\.',file)
        outputfile=open(fileDirN+fileName[0]+'.txt','w')
        
        sys.stdout=outputfile
        pattern = re.compile(r'(.*)(cpu used \d*)')#正则表达式
        print (' ',end="")#多输入一个空格，每行数据保持一致
        for line in f:
            m=pattern.match(line)
            
            if(m is not None):
                print (line,end=' ')
        outputfile.close()
sys.stdout=output