使用python读取txt文件的内容,并删除重复的行数方法

#coding:utf-8 
import shutil 
readDir = "原文件绝对路经" 
writeDir = "写入文件的绝对路径" 
#txtDir = "/home/fuxueping/Desktop/１" 
lines_seen = set() 
outfile=open(writeDir,"w") 
f = open(readDir,"r") 
for line in f: 
  if line not in lines_seen: 
    outfile.write(line) 
    lines_seen.add(line) 
outfile.close() 
print "success"