Parse certain XML tags sequentially using ElementTree

Question

I am trying to parse an XML file in a sequential manner, considering only XML-tags which are of interest. A sample XML file is shown below (stored as file.xml ). I am only interested in certain XML-tags of known paths, as shown in the Python code snippet below (eg header/para/paratext , body/section/intro/text ). Different XML files might have a different order of tags, so I do not want to prescribe in which order my known XML-tags will occur. Any suggestions how to do this in an efficient way without having to loop through the whole XML file?

XML file

<data>
  <header>
    <para>
      <paratext>0 - extract this</paratext>
    </para>
  </header>
  <body>
    <section>
      <intro>
        <text>1 - extract this</text>
      </intro>
      <para>
        <paratext>2 - extract this</paratext>
      </para>
      <items>
        <paratext>do not extract this</paratext>
        <part>
          <para>
            <paratext>3 - extract this</paratext>
          </para>
        </part>
      </items>
    </section>
    <section>
      <text>do not extract this</text>
      <intro>
        <text>4 - extract this</text>
      </intro>
      <para>
        <paratext>5 - extract this</paratext>
      </para>
      <para>
        <paratext>6 - extract this</paratext>
      </para>
    </section>
  </body>
</data>

Desired output : ['0 - extract this', '1 - extract this', '2 - extract this', '3 - extract this', '4 - extract this', '5 - extract this', '6 - extract this']

Sample Python script :

import xml.etree.ElementTree as ET

tree = ET.parse('file.xml')
root = tree.getroot()

### Paths I would like to extract (but sequentially)
[i.text for i in root.findall('header/para/paratext')]
# ['0 - extract this']
[i.text for i in root.findall('body/section/intro/text')]
# ['1 - extract this', '4 - extract this']
[i.text for i in root.findall('body/section/para/paratext')]
# ['2 - extract this', '5 - extract this', '6 - extract this']
[i.text for i in root.findall('body/section/items/part/para/paratext')]
# ['3 - extract this']

Answer 1

I think the best way to do this is to use the union operator (" | ") in XPath . That will select the desired elements in document order.

Unfortunately, ElementTree has limited XPath support .

If you can use lxml, it has much better XPath support .

Example...

Python

from lxml import etree

tree = etree.parse("file.xml")

print([i.text for i in tree.xpath('header/para/paratext|'
                                  'body/section/intro/text|'
                                  'body/section/para/paratext|'
                                  'body/section/items/part/para/paratext')])

Printed Output

['0 - extract this', '1 - extract this', '2 - extract this', '3 - extract this', '4 - extract this', '5 - extract this', '6 - extract this']

Parse certain XML tags sequentially using ElementTree

Question

1 answers

solution1
1 ACCPTED 2019-12-27 16:51:37

Parse certain XML tags sequentially using ElementTree

Question

1 answers

solution1 1 ACCPTED 2019-12-27 16:51:37

solution1
1 ACCPTED 2019-12-27 16:51:37