分析log文件中的keyword

#! /usr/bin/env python

import sys,os

FilePath = 'd:/SVNtest/'
FileName = FilePath + 'error.log'
ResultFile = FilePath + 'Fail.log'
KeyWord = 'error'

try:
    fh = open(FileName,'r')
    allLines =  fh.readlines()
    fh.close()
except IOError:
    print "the file don't exist, Please double check!"
    
i = 0
counter = 0
NewLines = []

for oneLine in allLines:
    i += 1
    if oneLine.find(KeyWord) >= 0:
        counter +=1
        print 'Find the match line at %d,now total %d times' %(i,counter)
        NewLines.append(oneLine)
        

fh = open(ResultFile,'a')
fh.writelines(NewLines)
fh.close()