[XML-SIG] Finding _xmlplus in Python 2.3a2

Uche Ogbuji uche.ogbuji@fourthought.com
Mon, 03 Mar 2003 07:34:35 -0700

To be frank, I'm still not very moved to the "ditch _xmlplus" camp this far in 
the thread.  I tend to agree with Martin and Jeremy that the additional 
confusion that would be cause by doing so exceeds the current confusion that 
is not related to plain old bugs in PyXML (rather than "misfeatures").  And I 
wouldn't want to change this feature based only on bugs that can be fixed.  
Perhaps I'm having trouble finding specifics in the anti-_xmlplus arguments.

The followng did strike me:

> On Sun, 2 Mar 2003, Jeremy Kloth wrote:
> [...]
> > Using undocumented APIs are, in general, prone to just such problems.  It is
> No, they are not.
> When I use a Python core module, and then install a related third-party
> module (no matter if it's written by the same people, and/or covers very
> similar ground), I don't expect it to clobber the first module unless I
> explicitly ask for that (by using try / except, or manipulating sys.path
> and the module system myself).  I expect it not to even touch the first
> module, actually.  And I would be correct, for all cases EXCEPT PyXML.
> People DO think of Python core's xml and PyXML as distinct in this sense,
> because that's the way ALL other Python software works, AFAIK.

PyXML is indeed a special case, because it was subsetted into Python with the 
explicit understanding on both sides (PyXML and Python/core), that the bundled 
subset is a mere convenience, and that if PyXML is available, it's the real 

Even then, I don't think it's all that special.  Python acts differently 
whether or not it has been compiled with, say, zlib installed, or whether it 
is compiled with UCS-4 (differences are bugs, to be fair).

I think that whether or not PyXML is installed is a configuration management 
variable that needs to be controlled in coherent projects, just like any other 
needs to be.  All configuration vriables have the potenial to change a 
package's behavior.

Uche Ogbuji                                    Fourthought, Inc.
http://uche.ogbuji.net    http://4Suite.org    http://fourthought.com
The open office file format  - http://www-106.ibm.com/developerworks/xml/librar
4Suite Repository Features - https://www6.software.ibm.com/reg/devworks/dw-x4su
XML class warfare - http://www.adtmag.com/article.asp?id=6965
See you at XML Web Services One - http://www.xmlconference.com/santaclara/