[XML-SIG] Finding _xmlplus in Python 2.3a2

Martijn Faassen faassen@vet.uu.nl
Sun, 2 Mar 2003 23:02:05 +0100

Jeremy Kloth wrote:
> How does PyXML break things?  Please submit bug reports when this happens so 
> we can make changes accordingly.  Without them, we cannot improve PyXML.

As I pointed out in an earlier mail, you cannot actually solve the problem
by fixing bugs in PyXML. Code may actually be relying on bugs or misfeatures
or undisclosed APIs in the core XML code, and a bugfix can therefore cause 
application breakage.

In addition, this type of backwards compatibility is really hard to manage.
Mistakes in PyXML will and have been made. That's only natural, but it'd
be far easier to manage with a clearer separation between core library and

So by all means fix bugs in PyXML, the main point is that if you're upgrading
PyXML you don't expect code that depends on the core Python library to be 
affected at all *even by bugfixes*, if you don't know the details of the

Of course depending on bugs or undisclosed APIs is wrong, but it happens,
especially in the light of incomplete documentation, and breaking the code in
what seems to be an unrelated upgrade is wrong too.