[Tutor] Fwd: find second occurance of string in line

[Albert-Jan Roskam]

> To: tutor at python.org
> From: __peter__ at web.de
> Date: Tue, 8 Sep 2015 21:37:07 +0200
> Subject: Re: [Tutor] Fwd:  find second occurance of string in line
> 
> Albert-Jan Roskam wrote:
> 
> >> import lxml.etree
> >>
> >> tree = lxml.etree.parse("example.xml")
> >> print tree.xpath("//objectdata/general/timestamp/text()")
> > 
> > Nice. I do need to try lxml some time. Is the "text()" part xpath as well?
>  
> Yes. I think ElementTree supports a subset of XPath.

aha, I see. I studied lxml.de a bit last night and it seems to be better in many ways. Writing appears to be mmmuch faster than cElementtree while many other situations are comparable to cElementtree. I love the objectify part of the package. Would you say that (given iterparse) lxml is also the module to process giant (ie. larger than RAM) xml files)? 

The webpage recommends a cascade of try-except ImportError statementsL first lxml, then cElementtree, then elementtree. But given that there are slight API differences, is that really a good idea? How would you test whether the code runs under both lxml and under the alternatives? Would you uninstall lxml to force that one of the alternatives is used?

Best wishes,
Albert-Jan