Python ElementTree XML输出到CSV

Question

我有以下XML文件（“ registerreads_EE.xml”）：

<?xml version="1.0" encoding="us-ascii" standalone="yes"?>
<ReadingDocument xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<ReadingStatusRefTable>
<ReadingStatusRef Ref="1">
  <UnencodedStatus SourceValidation="SIMPLE">
    <StatusCodes>
      <Signal>XX</Signal>
    </StatusCodes>
  </UnencodedStatus>
</ReadingStatusRef>
  </ReadingStatusRefTable>
  <Header>
<IEE_System Id="XXXXXXXXXXXXXXX" />
<Creation_Datetime Datetime="2015-10-22T09:05:32Z" />
<Timezone Id="UTC" />
<Path FilePath="X:\XXXXXXXXXXXX.xml" />
<Export_Template Id="XXXXX" />
<CorrelationID Id="" />
  </Header>
  <ImportExportParameters ResubmitFile="false" CreateGroup="true">
    <DataFormat TimestampType="XXXXXX" Type="XXXX" />
  </ImportExportParameters>
  <Channels>
<Channel StartDate="2015-10-21T00:00:00-05:00" EndDate="2015-10-22T00:00:00-05:00">
  <ChannelID ServicePointChannelID="73825603:301" />
  <Readings>
    <Reading Value="3577.0" ReadingTime="2015-10-21T00:00:00-05:00" StatusRef="1" />
    <Reading Value="3601.3" ReadingTime="2015-10-22T00:00:00-05:00" StatusRef="1" />
  </Readings>
  <ExportRequest RequestID="152" EntityType="ServicePoint" EntityID="73825603" RequestSource="Scheduled" />
</Channel>
    <Channel StartDate="2015-10-21T00:00:00-05:00" EndDate="2015-10-22T00:00:00-05:00">
  <ChannelID ServicePointChannelID="73825604:301" />
  <Readings>
    <Reading Value="3462.5" ReadingTime="2015-10-21T00:00:00-05:00" StatusRef="1" />
    <Reading Value="3501.5" ReadingTime="2015-10-22T00:00:00-05:00" StatusRef="1" />
  </Readings>
  <ExportRequest RequestID="152" EntityType="ServicePoint" EntityID="73825604" RequestSource="Scheduled" />
</Channel>
  </Channels>
</ReadingDocument>

我想将通道数据的XML解析为一个csv文件。

他是我用Python 2.7.10编写的：

import xml.etree.ElementTree as ET

tree = ET.parse('registerreads_EE.xml')

root = tree.getroot()[3]

for channel in tree.iter('Channel'):
    for exportrequest in channel.iter('ExportRequest'):
        entityid = exportrequest.attrib.get('EntityID')
        for meterread in channel.iter('Reading'):
            read = meterread.attrib.get('Value')
            date = meterread.attrib.get('ReadingTime')
            print read[:-2],",",date[:10],",",entityid

tree.write(open('registerreads_EE.csv','w'))

这是运行上述命令时的屏幕输出：

3577 , 2015-10-21 , 73825603
3601 , 2015-10-22 , 73825603
3462 , 2015-10-21 , 73825604
3501 , 2015-10-22 , 73825604

“ registerreads.csv”输出文件类似于原始XML文件，但减去第一行。

我想将上面的打印输出输出到带有读取，日期，entityid标头的csv文件。

我对此有困难。 这是我的第一个python程序。 任何帮助表示赞赏。

Answer 1

使用csv模块而非lxml模块将行写入csv文件。 但是仍然使用lxml解析和提取xml文件中的内容：

import xml.etree.ElementTree as ET
import csv

tree = ET.parse('registerreads_EE.xml')

root = tree.getroot()[3]

with open('registerreads_EE.csv', 'w', newline='') as r:
    writer = csv.writer(r)
    writer.writerow(['read', 'date', 'entityid'])  # WRITING HEADERS

    for channel in tree.iter('Channel'):
        for exportrequest in channel.iter('ExportRequest'):
            entityid = exportrequest.attrib.get('EntityID')
            for meterread in channel.iter('Reading'):
                read = meterread.attrib.get('Value')
                date = meterread.attrib.get('ReadingTime')    

                # WRITE EACH ROW ITERATIVELY 
                writer.writerow([read[:-2],date[:10],entityid])