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Editorial Team
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Asked: 2026-06-06T08:00:02+00:00

How do I use the and operator ‘|’ to compute 2 node sets? In

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How do I use the and operator ‘|’ to compute 2 node sets? In other words, compute data of 2 siblings with different tag names. In this case : I want data from both edition and edition2 tags. I tried ‘| and it didn’t work.

XML :

<?xml version="1.0" encoding="utf-8"?>
<wikimedia>
  <projects>
    <project name="Wikipedia" launch="2001-01-05">
      <editions>
        <edition language="English">en.wikipedia.org</edition>
        <edition language="German">de.wikipedia.org</edition>
        <edition language="French">fr.wikipedia.org</edition>
        <edition language="Polish">pl.wikipedia.org</edition>
        <edition language="Spanish">es.wikipedia.org</edition>
        <edition2 language="Spanglish">egs.wikipedia.org</edition2>
        <img src="hello.gif">hello</img>
      </editions>
    </project>
    <project name="Wiktionary" launch="2002-12-12">
      <editions>
        <edition language="English">en.wiktionary.org</edition>
        <edition language="French">fr.wiktionary.org</edition>
        <edition language="Vietnamese">vi.wiktionary.org</edition>
        <edition language="Turkish">tr.wiktionary.org</edition>
        <edition language="Spanish">es.wiktionary.org</edition>
        <edition2 language="Spanglish">egs.wiktionary.org</edition2>
        <img src="hello.gif">hello</img>
      </editions>
    </project>
  </projects>
</wikimedia>

Python :

>>> wikixml.xpath('//edition/text() | edition2/text()')
['en.wikipedia.org', 'de.wikipedia.org', 'fr.wikipedia.org', 'pl.wikipedia.org', 'es.wikipedia.org', 'en.wiktionary.org', 'fr.wiktionary.org', 'vi.wiktionary.org', 'tr.wiktionary.org', 'es.wiktionary.org']

EDIT

I got it working after the answer but I also want to select the value of img/@src
I managed to do this using the union operator |

>>> wikixml.xpath('//edition/text() | //edition2/text() | //img/@src')
['en.wikipedia.org', 'de.wikipedia.org', 'fr.wikipedia.org', 'pl.wikipedia.org', 'es.wikipedia.org', 'egs.wikipedia.org', 'hello.gif', 'en.wiktionary.org', 'fr.wiktionary.org', 'vi.wiktionary.org', 'tr.wiktionary.org', 'es.wiktionary.org', 'egs.wiktionary.org', 'hello.gif']

How to do this using a single predicate and the self notation like it’s done here with two elements

/wikimedia/projects/project/editions/ *[self::edition or self::edition2]/text()

now that we have @src and text()?

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1 Answer

  1. Editorial Team

    Use

    wikixml.xpath('//edition/text() | //edition2/text()')

    or more efficiently

    wikixml.xpath('//*[self::edition or self::edition2]/text()]

    or even better

    wikixml.xpath('/wikimedia/projects/project/editions/*[self::edition or self::edition2]/text()]

    As for the question update

    I also want img’s @src too. How to do this with the self notation now
    that we have @src and text()?

    Honestly, I don’t know if there’s a way to select from both the element and attribute axes at the same time using the above notation. I doubt it.

    You can either do it with a single XPath, but giving up the self::notation (at least for the attribute):

    /wikimedia/projects/project/editions/ *[self::edition or self::edition2]
|
/wikimedia/projects/project/editions/img/@src

    or select edition, edition2 and all elements containing an src attribute

    /wikimedia/projects/project/editions/ *[self::edition or self::edition2 or attribute::src]

    and then process the result to fetch the value of src

    That’s about as much as you can do in XPath 1.0
    As per Dimitre Novatchev’s suggestion, XPath 2.0 allows you to write it this way:

    /wikimedia/projects/project/editions/(*[self::edition or self::edition2] | img/@src )
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