Re: [xml] faster replacement libxml.py for python 2.2

[Hannu Krosing <hannu tm ee>]

Daniel Veillard kirjutas P, 05.01.2003 kell 01:30:
> On Sat, Jan 04, 2003 at 05:08:06PM +0500, Hannu Krosing wrote:
> > I have modified libxml.py (the handmade part of libxml2.py) to make 
> > use of some new features of python 2.2 , namely
> >
> > 1) replaced __gettattr__() with property()
>
>   Okay, I integrated both using
>     import sys
>     if float(sys.version[0:3]) < 2.2:
>         def __getattr__(self, attr):
>             ... existing libxml.py code ...
>     else:
>         ... your property based definitions ...
>
>   see the enclosed result.
>
> > 2) added an __iter__() method that returns an iterator over subtree of
> > node
>
>   That I couldn't make to work over 1.5 and 2.1 :

It will not work on 1.5 as it just does not support iterators.

It _may_ work with 2.1 with some "from __future__ import xxx2 stuff

> veillard:~/XML/python -> python1.5 tst.py
> Traceback (innermost last):
>   File "tst.py", line 17, in ?
>     nodecount(rec)
>   File "tst.py", line 10, in nodecount
>     for node in doc:
>   File "libxml2.py", line 307, in __getattr__
>     raise AttributeError,attr
> AttributeError: __getitem__
> veillard:~/XML/python ->
>
>   It seems that defining __getitem__ along to __getattr__ for the
> old code would allow to provide that facility on the older framework
> and I would really prefer that. Maybe reuse the iterator is possible
> it should just be a bit of glue it seems.
>
> > The result of replacing __gettattr__() with property() is a 2x speedup
> > when iterating over tree using node.next and node.children
> >
> > An additional 12% speedup can be gained by not having a separate xmlCore
> > class (it is used only by xmlNode) but including the hand-made part
> > directly in definition of class xmlNode.
>
>     Well, that's harder due to the autogeneration of xmlNode,

I was thinking about generating a chunk of code that would be inserted
into the xmlNode in the phase that merges the two (handmade and
generated) parts.


-- 
Hannu Krosing <hannu tm ee>