[Tutor] Trying to parse a HUGE(1gb) xml file in python

Stefan Behnel stefan_ml at behnel.de
Tue Dec 21 10:10:52 CET 2010

David Hutto, 21.12.2010 09:55:
> On Tue, Dec 21, 2010 at 3:52 AM, Stefan Behnel wrote:
>> Chris Fuller, 21.12.2010 03:27:
>>> This isn't XML, it's an abomination of XML.  Best to not treat it as XML.
>>> Good thing you're only after one class of tags.  Here's what I'd do.  I'll
>>> give a general solution, but there are two parameters / four cases that
>>> could
>>> make the code simpler, I'll just point them out at the end.
>>> Iterate over the file descriptor, reading in line-by-line.  This will be
>>> slow
>>> on a huge file, but probably not so bad if you're only doing it once.
>> Note that it's not unlikely that this is actually *slower* than using a real
>> XML parser:
> Or a 'real' language like C or C++ maybe to increase, or in Python's
> case, bypass, the interpreter?

While this may be a little faster than Python code (although I suspect that 
benchmarking is needed to prove either way), I doubt that it's worth the 
overhead in code writing. If I can write a couple of lines of Python code 
that are easy to validate and almost as fast as C code, why would I want to 
write and debug hundreds of lines of code in C or C++, just to see that I 
need to tune my benchmark to notice the difference?

But then, people even write XML handling code in Java, where neither 
performance nor code size is a suitable argument.


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