python 实时遍历日志文件

import os
import time
def check():
p = 
while True:
f = open("log.txt", "r+")
f = open("result.txt", "a+")
f.seek(p, )
#readlines()方法
filelist = f.readlines()
if filelist:
for line in filelist:
#对行内容进行操作
f.write(line)
#获取当前位置，为下次while循环做偏移
p = f.tell()
print 'now p ', p
f.close()
f.close()
time.sleep()
if __name__ == '__main__':
check() 

import os
import time
def check():
p = 
while True:
f = open("log.txt", "r+")
f = open("result.txt", "a+")
f.seek(p, )
#while readline()方法
while True:
l = f.readline()
#空行同样为真
if l:
#对行内容操作
f.write(l)
else:
#获取当前位置，作为偏移值
p = f.tell()
f.close()
f.close()
break
print 'now p', p
time.sleep()
if __name__ == '__main__':
check()