http://linuxtools-rst.readthedocs.io/zh_CN/latest/base/02_file_manage.html#id3 http://www.cnblogs.
http://linuxtools-rst.readthedocs.io/zh_CN/latest/base/02_file_manage.html#id3
http://www.cnblogs.com/ityouknow/p/7109417.html
http://www.runoob.com/python/python-tutorial.html
