[XML-SIG] Finding _xmlplus in Python 2.3a2
Sun, 2 Mar 2003 12:23:35 -0700
On Sunday 02 March 2003 12:12 pm, Michael McLay wrote:
> On Sunday 02 March 2003 11:51 am, Martijn Faassen wrote:
> > Uche Ogbuji wrote:
> > > I've stayed out of the _xmlplus thread because I really don't feel
> > > strongly enough about the issue one way or another (nor did I when the
> > > initial discussions took place).
> > >
> > > I understand that _xmlplus can be confusing when problems come abut,
> > > but on the other hand, it would seem to me the best approach is to just
> > > try to avoid those problems in the first place. I also wonder that the
> > > proposed change is too disruptive, given all the extant code that might
> > > depend on the ld arrnagement. On the flip side of that, I'm usually
> > > less of a stickler for backwar compat than most if it involves a chaneg
> > > that does the right thing.
> > >
> > > So does ditching _xmlplus even do the right thing? Is there so little
> > > discssion about this here because so few care?
> > 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 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.
> > This isn't just theoretical, I've seen this happen to several developers.
> > These developers use PyXML but have no clue about the mysteries of
> > _xmlplus, and who can blame them..
> When a system admin installs PyXML over the standard xml package, it can
> break previously working applications on a system. On systems where Python
> is shared by many developers, such as starship.python.net, this type of
> change can happen with the other developers not even being aware that a
> change has taken place. This should be fixed, and a note should be added to
> the Python programming style guide to advise other developers about the
> problems that can be caused by this idiom. Perhaps it would make sense to
> add it to PEP 5.
How does PyXML break things? Please submit bug reports when this happens so
we can make changes accordingly. Without them, we cannot improve PyXML.