在Perl中从XML到CSV的嵌套和定界元素 [英] XML to CSV with nested and definite elements in Perl

问题描述

我需要将xml文件转换为csv格式。但是在csv文件中，我不需要XML的所有信息，仅需要2个元素（设备的IP地址和ID）。

I need to convert my xml file to csv Format. But I in csv file I need not all Information fron the XML, just 2 elements (IP Address and id from device).

 #!/usr/bin/perl
 use strict;
 use warnings;
 use Data::Dumper;
 use XML::Simple;

  #Elements, that I want see in my csv
  my @Fields = qw{id, ipAddress};

  open(my $out, '>', 'output.csv') or die "Output: $!\n";
  print $out join(',', @Fields) . "\n";

  my $xml = XMLin('input.xml', ForceArray => ['entity']);
  foreach my $entity (@{$xml->{entity}}) {
  no warnings;
  print $out join(',', map{$_->{content}} @{$entity}{@Fields}) . "\n";

Input.xml

Input.xml

      <?xml version="1.0" ?>
          <queryResponse last="41" first="0" count="42" type="Devices" responseType="listEntityInstances" requestUrl="https://hostname/webacs/api/v1/data/Devices?.full=true" rootUrl="https://hostname/webacs/api/v1/data">
             <entity dtoType="devicesDTO" type="Devices" url="https://hostname/webacs/api/v1/data/Devices/20">
               <devicesDTO displayName="20" id="20">
               <clearedAlarms>1</clearedAlarms>
               <collectionDetail>&lt;status&gt;&lt;general code="SUCCESS"/&gt;&lt;/status&gt;</collectionDetail>
               <collectionTime>2017-03-30T09:47:07.606+02:00</collectionTime>
               <creationTime>2016-02-29T17:32:13.116+01:00</creationTime>
               <ipAddress>1.1.1.1</ipAddress>
               <location> </location>
               <majorAlarms>0</majorAlarms>
                <softwareType>IOS</softwareType>
                <softwareVersion>12.2(55)SE9</softwareVersion>
                <warningAlarms>0</warningAlarms>
             </devicesDTO>
          </entity>
          <entity dtoType="devicesDTO" type="Devices" url="https://hostname/webacs/api/v1/data/Devices/21">
               <devicesDTO displayName="21" id="21">
               <clearedAlarms>1</clearedAlarms>
               <collectionDetail>&lt;status&gt;&lt;general code="SUCCESS"/&gt;&lt;/status&gt;</collectionDetail>
               <collectionTime>2017-03-30T09:47:07.606+02:00</collectionTime>
               <creationTime>2016-02-29T17:32:13.116+01:00</creationTime>
               <ipAddress>2.2.2.2</ipAddress>
               <location> </location>
               <majorAlarms>0</majorAlarms>
                <softwareType>IOS</softwareType>
                <softwareVersion>12.2(55)SE9</softwareVersion>
                <warningAlarms>0</warningAlarms>
             </devicesDTO>
          </entity>
        </queryResponse> 

结果我有

 id, ipAddress
 ,
 ,

I我不确定：

     my $xml = XMLin('input.xml', ForceArray => ['entity']);
     foreach my $entity (@{$xml->{entity}})

对我来说是对的。我应该使用标签 entity 来做到这一点吗？

is right in my case. Should I do it with tag entity?

推荐答案

在处理XML :: Simple时，它总是使用 Data :: Dumper first 进行查找的一个好主意

When dealing with XML::Simple, it's always a good idea to use Data::Dumper first to look at the data structure.

foreach my $entity ( @{ $xml->{entity} } ) {
    print Dumper $entity;

这将向您显示：

$VAR1 = {
          'url' => 'https://hostname/webacs/api/v1/data/Devices/20',
          'type' => 'Devices',
          'dtoType' => 'devicesDTO',
          'devicesDTO' => {
                          'displayName' => '20',
                          'creationTime' => '2016-02-29T17:32:13.116+01:00',
                          'warningAlarms' => '0',
                          'ipAddress' => '1.1.1.1',
                          'clearedAlarms' => '1',
                          'majorAlarms' => '0',
                          'collectionDetail' => '<status><general code="SUCCESS"/></status>',
                          'location' => {},
                          'collectionTime' => '2017-03-30T09:47:07.606+02:00',
                          'softwareType' => 'IOS',
                          'id' => '20',
                          'softwareVersion' => '12.2(55)SE9'
                        }
        };

因此，很明显，您的 @Fields 在错误的地方。这些密钥不是直接在 $ entity 中，而是在 $ entity-> {devicesDTO} 中。

So it's quite clear that your @Fields are in the wrong place. Those keys are not in $entity directly, but rather in $entity->{devicesDTO}.

也无需在映射中使用 $ _-> {content} / code>。实际上，该数据结构中没有 content 键。

There is also no need to use $_->{content} with the map. In fact, there are no content keys in that data structure.

foreach my $entity ( @{ $xml->{entity} } ) {
    print join( ',', @{ $entity->{devicesDTO} }{@Fields} ) . "\n";
}

这将产生输出

id,ipAddress
20,1.1.1.1
21,2.2.2.2

---

请注意，您的 qw {} 中有一个逗号你不需要 qw 的想法是您不需要使用逗号。您还应该确定是否要让变量具有小写字母。混合是不好的样式，Perl中的约定是使用蛇形情况。

---

Note that you have a stray comma in your qw{} that you don't need. The idea of qw is that you do not need to use commas. You should also decide if you want your variables to have lower case letters or not. Mixing that is bad style, and the convention in Perl is to use snake case.

my @fields = qw{id ipAddress};

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