minidom

[Peter Hansen]

Duncan Smith wrote:
> 
> This may be a stupid question, but I'm struggling.  I can retreive
> information from an XML file (using minidom) as long as it is a node
> attribute.  But I cannot figure out how to get data otherwise.  eg.
> 
> <VAR NAME="ESLeak" TYPE="discrete" XPOS="16030" YPOS="16030">
> 
>     <DESCRIPTION>EngineStart Leak</DESCRIPTION>
> 
>     <STATENAME>good</STATENAME>
> 
>     <STATENAME>bad</STATENAME>
> 
> XPOS etc. no problem.  But how (using minidom) do I retreive 'Engine Start
> Leak' and 'good' etc?  Anyone know of any good documentation / worked
> examples for minidom?  Thanks in advance.

For one, you should probably start your XML document with 
<?xml version="1.0"?> or it won't be valid XML (but that's
not necessary for this case.)  You also need to close 
the <VAR> tag at the end with </VAR> or you'll get a 
parse error (SAXParseException).  Having done that:

>>> from xml.dom import minidom
>>> doc = minidom.parseString(open('test.xml').read())
>>> doc.getElementsByTagName('DESCRIPTION')[0].childNodes[0].nodeValue
u'EngineStart Leak'

That should give you a start.  Use the interactive prompt
and use dir() a lot.  For example:

>>> dir(doc)
['childNodes', 'doctype', 'implementation', 'ownerDocument', 'parentNode']
>>> dir(doc.childNodes[0])
['_attrs', '_attrsNS', 'childNodes', 'localName', 'namespaceURI', 'nextSibling',
 'nodeName', 'nodeValue', 'ownerDocument', 'parentNode', 'prefix', 
 'previousSibling', 'tagName']

The API is effectively the DOM standard, so you shouldn't have
much trouble if you have a reference to that handy.

-- 
----------------------
Peter Hansen, P.Eng.
peter at engcorp.com