给定测试数据集如下:
id city name
0 1 bj NaN
1 2 bj jack
2 3 bj NaN
3 4 bj jim
4 5 sh NaN
5 6 sh NaN
6 7 sh steve
7 8 sh fiona
8 9 sh NaN
我如何通过city进行群群,为name删除NaN行,同时只为每个group保留一个行?非常感谢。
预期结果如下:
id city name
0 1 bj NaN
1 2 bj jac
我正试图在Jelastic上运行ElasticSearch 5.0.1。在启动期间,它会打印到日志中:
max file descriptors [4096] for elasticsearch process is too low,
increase to at least [65536] max virtual memory areas vm.max_map_count
[65530] is too low, increase to at least [262144]
如何更改这些参数?增加预留云量并没有帮助。
我试图在Plesk主机上托管Umbraco,但获得了安全异常,我还试图将CAS信任级别更改为完全,但没有成功,请参阅下面的完整错误:
Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the applicati
我正在尝试使用php发送电子邮件。邮件返回true。但是我正在收到电子邮件。所以我猜可能是服务器出了问题。是否有任何教程解释如何配置服务器以使用cPanel正确发送电子邮件?
我的代码如下所示。
<?php
$msg = "First line of text\nSecond line of text";
$msg = wordwrap($msg,70);
$headers = "From: test1@islamerkotha.com";
mail("erfan.bashar.13@gmail.com",