Using lxml.etree with no root/parent element
Question
I have some SGML that looks like this
<!DOCTYPE sometype>
<ITEM>
<DATE>19-OCT-1987</DATE>
<TEXT>
<TITLE>I AM THE TITLE</TITLE>
<AUTHOR>I AM THE AUTHOR</AUTHOR>
<DATELINE>WHEN I WAS CREATED</DATELINE><BODY>
I WANT TO PRESERVE THIS TAG!
</BODY></TEXT>
</ITEM>
<ITEM>...
I tried to parse it with lxml.html, but it appears to strip the BODY tags, which I need to preserve. Next I tried to use lxml.etree, but as you can see there is not common parent element for all the ITEM tags. The code I'm currently using
doc = """<!DOCTYPE sometype>
<ITEM>
<DATE>19-OCT-1987</DATE>
<TEXT>
<TITLE>I AM THE TITLE</TITLE>
<AUTHOR>I AM THE AUTHOR</AUTHOR>
<DATELINE>WHEN I WAS CREATED</DATELINE><BODY>
I WANT TO PRESERVE THIS TAG!
</BODY></TEXT>
</ITEM>"""
from lxml import etree
parser = etree.XMLParser(recover=True) # I have invalid HTML chars to ignore
sgml = etree.fromstring(doc, parser)
Now sgml is only the first ITEM element. I need it to be all of the ITEM elements. Any ideas? lxml.html does what I want, but it strips the BODY tags by default, and I haven't found a way to disable this behavior.
1 answers
solution1
1 2013-05-17 00:47:33
There isn't a common parent element? Just make one! You can just rewrite them to have a parent element, say ROOT. Insert <ROOT> before the first <ITEM> and </ROOT> at the end of the document. It's pretty trivial to do programmatically, even if you have to preserve the actual on-disk content.
eg.
<!DOCTYPE sometype>
<ROOT>
<ITEM>
<DATE>19-OCT-1987</DATE>
<TEXT>
<TITLE>I AM THE TITLE</TITLE>
<AUTHOR>I AM THE AUTHOR</AUTHOR>
<DATELINE>WHEN I WAS CREATED</DATELINE><BODY>
I WANT TO PRESERVE THIS TAG!
</BODY></TEXT>
</ITEM>
<ITEM>
<DATE>19-OCT-1879</DATE>
<TEXT>
<TITLE>I AM THE TITLE</TITLE>
<AUTHOR>I AM THE AUTHOR</AUTHOR>
<DATELINE>WHEN I WAS CREATED</DATELINE><BODY>
I WANT TO PRESERVE THIS TAG!
</BODY></TEXT>
</ITEM>
<ITEM>
<DATE>19-OCT-9871</DATE>
<TEXT>
<TITLE>I AM THE TITLE</TITLE>
<AUTHOR>I AM THE AUTHOR</AUTHOR>
<DATELINE>WHEN I WAS CREATED</DATELINE><BODY>
I WANT TO PRESERVE THIS TAG!
</BODY></TEXT>
</ITEM>
</ROOT>
I've just tried this and it seems to do what you want. Saved as /tmp/goodfoo and loaded with lxml.etree.fromstring(allcontent) ; then I accessed the text you say 'want to preserve' like this: b.getchildren()[0].getchildren()[-1].getchildren()[-1].text
(that is, get the first ITEM, get its TEXT element, get the TEXT element's BODY element, and return any text content of the BODY element.)
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