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()`?