str = "hello jiao";# 从索引0开始到index=-1之前（包含index=0不包含index=-1【index=-1是字符串最后一个字符】）print(str[0: -1]);# hello jia# 从索引0开始到index=4之前（包含index=0不包含index=4）print(str[0: 4]);print(str[: 4]);# hell# 从索引6开始到结尾（包含index=6）print(str[6: ]);# jiao# 输出两次字符串print(str * 2);# 字符串拼接print(str[0: 5] + "  world!!!");

str = "hello";str += " jiao";print(str);     #hello jiaostr = "jiao";print(str);   #jiao

print("""    <meta charset="utf-8" />        <script src=http://www.mamicode.com/"https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>        <link rel="stylesheet" href=http://www.mamicode.com/"//cdn.bootcss.com/uikit/2.25.0/css/uikit.css" />        <script src=http://www.mamicode.com/"//cdn.bootcss.com/uikit/2.25.0/js/uikit.js"></script>        <link href=http://www.mamicode.com/"http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">        <script src=http://www.mamicode.com/"http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>        <link rel="stylesheet" href=http://www.mamicode.com/"css/global.css">        <link rel="stylesheet" href=http://www.mamicode.com/"css/index.css">        <script src=http://www.mamicode.com/"js/main.js"></script>""");