python txtファイルを行単位で読み書きする

# -*-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()

#    ，         ，     
if os.path.exists("dest.txt"):
    os.remove("dest.txt")
mylist = ["luoluo", "taotao", "mumu"]

#          ，       ，      
file_write_obj = open("dest.txt", 'w')
for var in mylist:
    file_write_obj.writelines(var)
    file_write_obj.write('
')
file_write_obj.close()