Jython

From: Dinu Gherman <gherman@...>
To: <jython-users@...>
Sent: Friday, May 31, 2002 12:16 PM
Subject: [Jython-users] Porting degree of Python's std. lib. XML modules


> Hi,
> 
> I'm slightly puzzled, again. I vaguely remember some people replying
> to a previous question of mine about using Python's standard library 
> XML modules on Jython who said there were no immediate problems.
> 
> I now stumbled over the lack of methods like toxml() and toprettyxml()
> for xml.dom.minidom.Element objects (see Python/Jython comparison
> below). Is there some other way to do it, maybe? Or are the XML 
> modules not entirely ported, maybe?
> 

maybe in this case  you don't know what you are doing <wink>,
consider e.g. that Jython 2.1, comes with a larger subset of PyXML
than Python 2.1 wrt to DOM support.

regards.

Samuele Pedroni <pedroni@...>:

> maybe in this case  you don't know what you are doing <wink>,
> consider e.g. that Jython 2.1, comes with a larger subset of PyXML
> than Python 2.1 wrt to DOM support.

While this might be true, I suspect what you really mean is: "Jython 2.1, 
comes with a *smaller* subset of *std.-lib.* XML than Python *2.2* wrt 
to DOM support", don't you? ;-) If, OTOH, there are no typos in your
statement above, then I'm not sure I understand why there should be 
such differences? So, for the rest I'll assume there were typos.

First I doubt very much that *any* Python or Jython version now includes 
PyXML, which is the XML-SIG's stuff, (I sometimes would wish so, and then, 
sometimes I don't). PyXML is in version 0.7.x and is to the best of my 
knowledge *not yet* bundled directly with any Python version. I would be 
really surprised if the XML-SIGs reasoning was different for Jython.

Then, while it might be the case that Python/Jython 2.2 has more (stan-
dard lib.) XML support than Python/Jython *2.1*, I claim that this is 
totally irrelevant in my case because I'm using low-level functionality 
that I *know* to be working on Python 2.0 and 2.1 as well. I should have 
mentioned this earlier, yes, and I'm sorry for not doing so.

Moreover, I also noticed what could be another error in the functions
minidom.parse() and minidom.parseString() as implemented in Jython 2.1:


dinu% python
Python 2.2 (#1, Feb 13 2002, 11:18:45) 
[GCC 2.95.2 19991024 (release)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 
>>> import xml.dom.minidom
>>> xml.dom.minidom.parseString("<foo>bar</foo>")
<xml.dom.minidom.Document instance at 0x575e70>
>>> 

dinu% jython
Jython 2.1 on java1.3.1 (JIT: null)
Type "copyright", "credits" or "license" for more information.
>>> 
>>> import xml.dom.minidom
>>> xml.dom.minidom.parseString("<foo>bar</foo>")
Traceback (innermost last):
  File "<console>", line 1, in ?
  File "/jython-2.1/Lib/xml/dom/minidom.py", line 913, in parseString
  File "/jython-2.1/Lib/xml/dom/minidom.py", line 900, in _doparse
  File "/jython-2.1/Lib/xml/dom/pulldom.py", line 251, in getEvent
AttributeError: feed
>>> 


I hope it's clearer now what I think the problem really is.

Regards,

Dinu

From: Dinu Gherman <gherman@...>

> Samuele Pedroni <pedroni@...>:
>
> > maybe in this case  you don't know what you are doing <wink>,
> > consider e.g. that Jython 2.1, comes with a larger subset of PyXML
> > than Python 2.1 wrt to DOM support.
>
> While this might be true, I suspect what you really mean is: "Jython 2.1,
> comes with a *smaller* subset of *std.-lib.* XML than Python *2.2* wrt
> to DOM support", don't you? ;-) If, OTOH, there are no typos in your
> statement above, then I'm not sure I understand why there should be
> such differences? So, for the rest I'll assume there were typos.
>

no typos.

Python 2.1 (#15, Apr 16 2001, 18:25:49) [MSC 32 bit (Intel)] on win32
Type "copyright", "credits" or "license" for more information.
>>> from xml import dom
>>> dom.getDOMImplementation()
<xml.dom.minidom.DOMImplementation instance at 007B830C>
>>>

vs.

Jython 2.1 on java1.3.0 (JIT: null)
Type "copyright", "credits" or "license" for more information.
>>> from xml import dom
>>> dom.getDOMImplementation() # (1)
<xml.dom.DOMImplementation.DOMImplementation instance at 4758594>
>>> dom.getDOMImplementation('4DOM')
<xml.dom.DOMImplementation.DOMImplementation instance at 1995582>
>>> dom.getDOMImplementation('minidom')
<xml.dom.minidom.DOMImplementation instance at 3119471>
>>>

doh?

with *plain* (1) what you get depends on what is installed and
on the order of some keys inside a dict,
quite un(der)specified.


> First I doubt very much that *any* Python or Jython version now includes
> PyXML, which is the XML-SIG's stuff, (I sometimes would wish so, and then,
> sometimes I don't). PyXML is in version 0.7.x and is to the best of my
> knowledge *not yet* bundled directly with any Python version. I would be
> really surprised if the XML-SIGs reasoning was different for Jython.

*We* do include a part PyXML for user convenience.
Finn decided so, if I recall correctly.

> dinu% jython
> Jython 2.1 on java1.3.1 (JIT: null)
> Type "copyright", "credits" or "license" for more information.
> >>>
> >>> import xml.dom.minidom
> >>> xml.dom.minidom.parseString("<foo>bar</foo>")
> Traceback (innermost last):
>   File "<console>", line 1, in ?
>   File "/jython-2.1/Lib/xml/dom/minidom.py", line 913, in parseString
>   File "/jython-2.1/Lib/xml/dom/minidom.py", line 900, in _doparse
>   File "/jython-2.1/Lib/xml/dom/pulldom.py", line 251, in getEvent
> AttributeError: feed
> >>>

that's  a known bug :(

http://sourceforge.net/tracker/index.php?func=detail&aid=533354&group_id=12867&;
atid=112867

regards.

[Samuele]

> *We* do include a part PyXML for user convenience.
> Finn decided so, if I recall correctly.

Correct. Jython-2.1 shipped with selected parts of PyXML-0.6.6.

regards,
finn

Finn Bock <bckfnn@...>:

> Correct. Jython-2.1 shipped with selected parts of PyXML-0.6.6.

Ok, that explains a few things. I can see archived messages talking 
about it, but I don't see anything on jython.org that would explain 
which parts of PyXML 0.6.6 were ported. Is that so or should I re-
fine my algorithm?

I remember there used to be quite some interaction issues with 4Suite 
packages and versions needed to make XSLT fly, etc. Considering my 
own experience only, I feel like the boundaries between std.lib. XML, 
PyXML and 4Suite are too blurred, but maybe that's only my subjective 
impression.

So, I admit, when reading "selected parts" above I feel rather more 
uneasy about it. ;-)

Regards,

Dinu

[Dinu Gherman]

> Ok, that explains a few things. I can see archived messages talking 
> about it, but I don't see anything on jython.org that would explain 
> which parts of PyXML 0.6.6 were ported. Is that so or should I re-
> fine my algorithm?

I copied the parts of PyXML that was needed to complete some of the 
PyXML test cases. Please note that I didn't port anything, I only copied 
some of the files. The drivers that depends on C code such as expat 
isn't included. If I included all of PyXML some tests failed.

> I remember there used to be quite some interaction issues with 4Suite 
> packages and versions needed to make XSLT fly, etc. Considering my 
> own experience only, I feel like the boundaries between std.lib. XML, 
> PyXML and 4Suite are too blurred, but maybe that's only my subjective 
> impression.
> 
> So, I admit, when reading "selected parts" above I feel rather more 
> uneasy about it. ;-)

I understand.

By removing the ./Lib/xml directory, you are right back to what jython 
itself supports of xml: absolutely nothing at all. So while I too think 
that the internal boundries between the PyXML parts are blurred, there 
is no blurring between jython and PyXML.

If you can create a subset of PyXML that works better with jython, 
please do so and report you findings to jython-dev. I'll be happy to 
include more or less of PyXML if it helps.

regards,
finn