Re: Copying children including text nodes
Stefan Behnel <stefan_ml <at> behnel.de>
2010-02-08 13:41:55 GMT
Martin Aspeli, 06.02.2010 12:46:
> I have two trees that were parsed with the HTML parser. The source tree is:
>
> <html>
> <head>
> <body>
> Foo
> <p>Bar</p>
> Baz
> </body>
> </html>
>
> The target is:
>
> <html>
> <head>
> <body>
> <div id="target">Placeholder</div>
> </body>
> </html>
>
> Now, I want to replace the whole of <div id="target"> tag (so, the tag
> and its children) with the *contents* of the <body> tag in the source
> tree. I obviously don't want the body tag itself.
parent.replace() doesn't currently support sequence insertion, but I would
expect this to work:
prev = div_element.getprevious()
if prev is None:
target_body[:1] = source_body[:]
target_body.text = source_body.text # take care of existing text?
else:
pos = target_body.index(div_element)
target_body[pos:pos+1] = source_body[:]
if prev.tail:
prev.tail += source_body.text
else:
prev.tail = source_body.text
> Performance is important. Also, I don't care about the source tree after
> I'm done, so if "moving" rather than copying makes things faster/easier,
> that's OK.
Moving is certainly faster than copying, as copying does at least the same
amount of work, plus the memory allocations. If copying was required, you
could always do a deepcopy of the source content before inserting it.
I can't give any further comments on performance, though. You'll need to do
your own benchmarks (although I'm always interested in the results :)
Stefan
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