Mailman 3 April 2018 - lxml - The Python XML Toolkit

Re: [lxml] Difference between findall() and xpath()
by Stefan Behnel 18 Apr '18

18 Apr '18

Hi, you probably meant to reply to the list. Peng Yu schrieb am 22.03.2018 um 23:11: >> Does this help? >> >> http://lxml.de/tutorial.html#elementpath > > This does not explain their difference from `xpath()`. Can somebody be > more explicit about the differences? There are three differences. The main difference is the namespace representation: XPath uses an indirection through prefixes, ElementPath uses namespace URIs directly, thus matching the rest of the API. The second difference is that XPath has more features than ElementPath, but that's a bug. ;) And the third difference is that ElementPath supports iteration, whereas the XPath implementation always returns a complete result list. Well, and as I mentioned, ElementPath is usually faster than XPath, unless you hit a case that can structurally be expressed (and processed) more efficiently by the XPath implementation of libxml2. But that case is difficult to predict and requires proper measuring on real data. Stefan

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Element iteration and removal
by Jens Tröger 06 Apr '18

06 Apr '18

Hello, Suppose I iterate over the elements of a subtree, then is it safe to remove the elements during the iteration: for elem in t.xpath("br"): p = elem.getparent() p.remove(elem) # _Seems_ to work? or will that mess with the iterator, and I should collect the elements first: for elem in list(t.xpath("br")): # now remove I guess I can rephrase the question: is xpath() lazy? Just want to make sure. Thanks! Jens -- Jens Tröger http://savage.light-speed.de/

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lxml.etree.ElementTree.write() doesn't seem to believe the encoding I specify
by Rolf Blijleven 04 Apr '18

04 Apr '18

Hi, I would appreciate if anyone could take a look at this question <https://stackoverflow.com/q/49575005/1016065> that I posted on StackOverflow. If you have any comments or answers, posting them there would be better than answering to this mail. Many thanks in advance, Rolf

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