在不使用 DOM 方法的情况下迭代解析大型 XML 文件

问题描述

我有一个 xml 文件

I have an xml file

<temp>
  <email id="1" Body="abc"/>
  <email id="2" Body="fre"/>
  .
  .
  <email id="998349883487454359203" Body="hi"/>
</temp>

我想读取每个电子邮件标签的 xml 文件.也就是说，有一次我想读取电子邮件 id=1..从中提取正文，读取的电子邮件 id=2...并从中提取正文...等等

I want to read the xml file for each email tag. That is, at a time I want to read email id=1..extract body from it, the read email id=2...and extract body from it...and so on

我尝试使用 DOM 模型进行 XML 解析，因为我的文件大小为 100 GB..该方法不起作用.然后我尝试使用:

I tried to do this using DOM model for XML parsing, since my file size is 100 GB..the approach does not work. I then tried using:

  from xml.etree import ElementTree as ET
  tree=ET.parse('myfile.xml')
  root=ET.parse('myfile.xml').getroot()
  for i in root.findall('email/'):
              print i.get('Body')

现在，一旦我获得了 root..我不明白为什么我的代码无法解析.

Now once I get the root..I am not getting why is my code not been able to parse.

使用 iterparse 时的代码抛出以下错误:

The code upon using iterparse is throwing the following error:

 "UnicodeEncodeError: 'ascii' codec can't encode character u'u20ac' in position 437: ordinal not in range(128)"

谁能帮忙

推荐答案

一个iterparse的例子:

An example for iterparse:

import cStringIO
from xml.etree.ElementTree import iterparse

fakefile = cStringIO.StringIO("""<temp>
  <email id="1" Body="abc"/>
  <email id="2" Body="fre"/>
  <email id="998349883487454359203" Body="hi"/>
</temp>
""")
for _, elem in iterparse(fakefile):
    if elem.tag == 'email':
        print elem.attrib['id'], elem.attrib['Body']
    elem.clear()

只需将 fakefile 替换为您的真实文件即可.另请阅读 this 了解更多详情.

Just replace fakefile with your real file. Also read this for further details.