Python中read,readline,readlines三种方式的区别 |
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Python中read,readline,readlines三种方式的区别
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027ryan 2017-01-20 11:05:09 博主文章分类:Python ©著作权 文章标签 Python python 文章分类 Python 后端开发 ©著作权归作者所有:来自51CTO博客作者027ryan的原创作品,请联系作者获取转载授权,否则将追究法律责任在用python读取文件的时经常用到三read、readline、readlines三种方法,它们功能实质区别如下: read 读取整个文件 readline 读取下一行 readlines 读取整个文件到一个迭代器以供我们遍历(读取到一个list中,以供使用,比较方便) 测试文件为test.txt内容为: 1 aaaaaaaaaaaaaaaaaaaaa 2 bbbbbbbbbbbbbbbbbbbbb 3 ccccccccccccccccccccc 4 dddddddddddddddddddddd[root@node01 ~]# pwd /root [root@node01 ~]# ls -l test.txt -rw-r--r-- 1 root root 97 Jan 20 10:59 test.txt [root@node01 ~]# cat test.txt 1 aaaaaaaaaaaaaaaaaaaaa 2 bbbbbbbbbbbbbbbbbbbbb 3 ccccccccccccccccccccc 4 dddddddddddddddddddddd read方法 [root@node01 ~]# python Python 2.6.6 (r266:84292, Jan 22 2014, 09:42:36) [GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> obj=open('/root/test.txt','r+w') >>> obj.read() '1 aaaaaaaaaaaaaaaaaaaaa\n2 bbbbbbbbbbbbbbbbbbbbb\n3 ccccccccccccccccccccc\n4 dddddddddddddddddddddd\n' >>> obj.read() '' >>> exit() readline方法 [root@node01 ~]# python Python 2.6.6 (r266:84292, Jan 22 2014, 09:42:36) [GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> obj=open('/root/test.txt','r+w') >>> obj.readline() '1 aaaaaaaaaaaaaaaaaaaaa\n' >>> obj.readline() '2 bbbbbbbbbbbbbbbbbbbbb\n' >>> obj.readline() '3 ccccccccccccccccccccc\n' >>> obj.readline() '4 dddddddddddddddddddddd\n' >>> obj.readline() '' >>> exit() readlines方法 [root@node01 ~]# python Python 2.6.6 (r266:84292, Jan 22 2014, 09:42:36) [GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> obj=open('/root/test.txt','r+w') >>> obj.readlines() ['1 aaaaaaaaaaaaaaaaaaaaa\n', '2 bbbbbbbbbbbbbbbbbbbbb\n', '3 ccccccccccccccccccccc\n', '4 dddddddddddddddddddddd\n'] >>> obj.readlines() [] >>> obj.readlines() [] >>>触类旁通,还有write、writelines方法,用法与上述方法对应类似,只不过write写入的对象时字符串(str),writelines写入的是列表(list),即: obj.write(str) obj.writelines(sequence) 赞 收藏 评论 分享 举报上一篇:Centos/Linux下如何查看网关地址/Gateway地址 下一篇:Python判断一个文件中的字符串是否存在于另外一个文件中 |
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