我有一个xml
结构如下的文件:
<?xml version="1.0" encoding="utf-8"?>
<ScheduleMessage DtdVersion="3" DtdRelease="0">
<MessageIdentification v="ETSOVista-DMinus1TotalLoadForecast-DE-2012-1" />
<MessageVersion v="1" />
<MessageType v="A11" />
<ScheduleTimeSeries>
<SendersTimeSeriesIdentification v="10YCB-GERMANY--8" />
<SendersTimeSeriesVersion v="1" />
<BusinessType v="A05" />
<Period>
<TimeInterval v="2012-11-15T23:00Z/2012-11-16T23:00Z" />
<Resolution v="PT60M" />
<Interval>
<Pos v="1" />
<Qty v="52452" />
</Interval>
<Interval>
<Pos v="2" />
<Qty v="50527" />
</Interval>
<Interval>
<Pos v="3" />
<Qty v="49221" />
</Interval>
<Interval>
<Pos v="4" />
<Qty v="49344" />
</Interval>
</Period>
</ScheduleTimeSeries>
<ScheduleTimeSeries>
<SendersTimeSeriesIdentification v="10YCB-GERMANY--8" />
<SendersTimeSeriesVersion v="1" />
<BusinessType v="A05" />
<Period>
<TimeInterval v="2012-11-16T23:00Z/2012-11-17T23:00Z" />
<Resolution v="PT60M" />
<Interval>
<Pos v="1" />
<Qty v="50935" />
</Interval>
<Interval>
<Pos v="2" />
<Qty v="48918" />
</Interval>
<Interval>
<Pos v="3" />
<Qty v="47347" />
</Interval>
<Interval>
<Pos v="4" />
<Qty v="46382" />
</Interval>
</Period>
</ScheduleTimeSeries>
</ScheduleMessage>
我只需要这些Qty
值。到目前为止,我的代码如下所示:
xml <- xmlInternalTreeParse(file = "test.xml")
xml_top <- xmlRoot(xml)
xml_children <- xmlChildren(x = xml_top)
但是,当我尝试通过以下方式更深入地了解文件时:
xml_children2 <- xmlChildren(x = xml_children)
我收到以下错误:
Error in UseMethod("xmlChildren") :
no applicable method for 'xmlChildren' applied to an object of class "c('XMLInternalNodeList', 'XMLNodeList')"
我也尝试使用[]
or对文件进行子集化[[]]
,但它总是引导我进入相同的错误。