Python，文件修改

__author__ = '12711'
#-*- coding:utf-8 -*-
f=open("F",'r')
f_n=open("N",'w')
for i in f:
    if "我爱你" in i :
        i=i.replace("我爱你","我恨你")
    f_n.write(i)
f.close()
f_n.close()