[XML-SIG] Re: Finding _xmlplus in Python 2.3a2

Martijn Faassen faassen@vet.uu.nl
Sun, 2 Mar 2003 22:55:14 +0100

Jeremy Kloth wrote:
> Most libraries that get moved into the core are not as large as PyXML and to 
> top it off only part of PyXML was moved into the core.

That is true. I don't quite see how it therefore follows we should use
this scheme however.

> This is probably the 
> root of most of the problems.  However, PyXML had dibs on the top-level "xml" 
> before Python core did, so this deal was struck to keep developers for both 
> sides happy.

Okay, if that is how it happened, but I'm not happy. :)

> There would have been *much* code to change if PyXML was forced 
> to change the package to something else, and I believe this is still the 
> case, at least with PyXML.

These changes are mostly very superficial, however. Though easier if
we had a comprehensive suite of unit tests..

> Another issue that is solved by the current arrangement is support for 
> multiple Python versions with the same code base.  For example, if you 
> develop an application for 2.3 that uses the "core" xml library, you can 
> easily support Python 2.0, 2.1 and 2.2 by telling those users to simply 
> install PyXML 0.8.2 and it will work the same (given you use only those 
> features of Python available in the lowest version you wish to support).  
> This is a big plus for end users.

No, I don't think the current arrangement helps here at all; in fact it
contributes to the confusion. If PyXML had its own top level namespace
I could *still* easily support multiple Python versions by telling users
to install PyXML. In fact, it'll be far more obvious to developers and users
what's going on, as their Python core library isn't magically upgraded
out from under them. Or even weirder, you upgrade your Python but you
also have PyXML installed for it (or install it later), and now it may be
magically *degraded*.

One has to look hard to determine whether should install anything at all
in the current situation. If I develop for Python 2.3 which has more features
in its XML core libraries, I have to somehow find out that some version of
PyXML has versions of the code that if installed may make my code work with
older versions..

> Now as I understand it, you (or users you are speaking for) are having 
> problems with PyXML installations or lack thereof.  If so, please file bug 
> reports!  We cannot fix what we don't know is broke.

No, I have witnessed several developers using this software not understanding
the arrangment, which is obscure and confusing. In addition there are indeed
users who get confused as well. Dependency management would be a lot more
straightforward for everyone if PyXML had its own top level namespace.