[XML-SIG] Finding _xmlplus in Python 2.3a2

Jeremy Kloth jeremy.kloth@fourthought.com
Sun, 2 Mar 2003 13:59:01 -0700

On Sunday 02 March 2003 09:51 am, Martijn Faassen wrote:
> I don't know why there is so little discussion about this; perhaps because
> everybody who could care isn't aware of the situation -- it's not like
> it's very obvious to people, even to people who use the XML facilities.

I would think that this would mean that the situation is working quite well if 
people aren't even aware of it.

> I think ditching _xmlplus is the right thing, as it *causes* problems, it's
> not only confusing when problems come about from some other source. It's
> rather difficult right now; your application might be working with core
> Python, and if you install PyXML, it breaks. Or if you upgrade it. Oddly
> enough, you might not even be aware that an application you build depends
> on PyXML at all (you happened to had it installed, that's all, but were
> reading the standard library reference and a dependency on some
> bug/undisclosed API crept in). And then you find out later.

Using undocumented APIs are, in general, prone to just such problems.  It is 
always "use at your own risk" if an API isn't documented, don't expect it to 
stay the same between releases.  If a developer sticks with the documented 
APIs from the Python documentation for the xml package, I don't think that 
PyXML has ever broken them (going from memory here, so I may be wrong).

The one issue that comes to mind however was the change to the Text node 
constructor.  This, though, should have been only used internal to minidom as 
was never documented in the Python docs.  Actually, the Python docs (from 
"minidom and the DOM standard") state applications should not instaniate the 
classes themselves but use the interfaces on the Document object.

Jeremy Kloth