python怎么逐行读写txt文件

# -*-coding:utf-8-*-

import os

file_obj = open("test2.txt")

all_lines = file_obj.readlines()

for line in all_lines:

  print line

file_obj.close()

# 写之前，先检验文件是否存在，存在就删掉

if os.path.exists("dest.txt"):

  os.remove("dest.txt")

mylist = ["luoluo", "taotao", "mumu"]

# 以写的方式打开文件，如果文件不存在，就会自动创建

file_write_obj = open("dest.txt", 'w')

for var in mylist:

  file_write_obj.writelines(var)

  file_write_obj.write('\n')

file_write_obj.close()