Ruby:将大的.xml文件转换为csv

Question

我有一个小问题。我需要将大型xml文件(每个1-4GB)转换为CSV。我知道我可以用Nokogiri的SAX解析器做到这一点，但是我卡住了。

<Documents>
    <Document DocID="10170306" DocType="Message">
    <FieldValues>
        <E03>-1166737392</E03>
        <E05>petrosky ([e-mail])</E05>
        <E06>00000000B89476181EE6C34FB4E9D87F9E44A85944002000</E06>
        <E07>foo-dedup-global.mbox_99.mbox</E07>
        <E08>5/12/2011 6:32:38 PM</E08>
        <E09>Fwd: important decision for v1 launch</E09>
        <E10>Susan Infantino ([e-mail]); Mike Yang ([e-mail])</E10>
        <F01>Jun  8 2011  7:43AM</F01>
        <F02>May 12 2011  6:32PM</F02>
        <F03>Msg0002_important decisi.html</F03>
        <F04>MSMAIL</F04>
        <F05>CA4DBB95C638FB656CB02627DDEA90C9</F05>
        <F06>28677</F06>
        <F07>foo-dedup-global.mbox_99.mbox.pst</F07>
        <F08>10164846</F08>
        <F09>10170306</F09>
        <E11>0</E11>
        <E12>&lt;BANLkTi=yztN5Pd0v9i9+zN=[e-mail]&gt;</E12>
    </FieldValues>
    <Files>
      <File FileType="Native">
        <ExternalFile FilePath="4_EXT31foo-dedup-global.mbox_99.mbox.pst10164846.dirfoo-dedup-global.mbox_99.mbox" FileName="Msg0002_important decisi.html" FileSize="28677" Hash="CA4DBB95C638FB656CB02627DDEA90C9" HashType="MD5" />
      </File>
    </Files>
    <Locations>
      <Location>
        <Custodian>Yang_Mike</Custodian>
        <LocationURI>\ANNATXCIFS02PN_Dunbar_F014014_EXT31foo-dedup-global.mbox_99.mbox.pst10164846.dirfoo-dedup-global.mbox_99.mboxMsg0002_important decisi.html</LocationURI>
      </Location>
    </Locations>    
  </Document>
</Documents>

我尝试了一些事件驱动编程。

require 'fileutils'
require 'faster_csv'
require 'nokogiri'
file = ARGV[0]
include Nokogiri
class Xmlfile < XML::SAX::Document
  def start_element name, attrs
    # Process data here
    if name == 'Document'
      documentName = [*attrs]
      puts documentName
    end     
    if name == 'File'
      file = [*attrs]
      puts file
    end
    if name == 'ExternalFile'
      externalFile = [*attrs]
      puts externalFile 
    end
  end
#   def end_element name, attrs
#   end
end
parser = XML::SAX::Parser.new(Xmlfile.new)
parser.parse_file(file)

Answer 1

看起来您正在输出puts中所需的信息，并试图将数据捕获到变量中。您错过了使用变量将数据发送到CSV生成器的部分。

您可以将documentName, file和externalFile附加到Array中并将其传递给CSV。

CSV文档展示了几种生成输出的好方法。查看"写作"部分了解更多信息。

From the docs:

FasterCSV.open("path/to/file.csv", "w") do |csv|
  csv << ["row", "of", "CSV", "data"]
  csv << ["another", "row"]
  # ...
end