Python过滤txt文件内重复内容的方法

# -*-coding:utf-8 -*-
f = open("1.txt", "rb")
n = f.read()
f.close()
m = n.split("\r\n")
print "m=",m
print m[1]
m1 = []
for i in xrange(len(m)):
 if not m[i] in m1:
  m1.append(m[i])
print "m1=", m1
filename = open("1.0.txt", "wb")
for i in xrange(len(m1)):
 filename.write(m1[i]+"\n")