[XML-SIG] Pyxml: DOM questions, problems with namespaces
mike at skew.org
Thu Jun 1 23:34:44 CEST 2006
Matthias Dorfner wrote:
> 1. some problems creating my xml file with the
> correct double quoted string in the namespace, here one example:
> <?xml version='1.0' encoding='UTF-8'?>
> <request xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
> I need exactly this output but not single quoted(' -> "). Here's the code
The type of quotes used on attribute values during serialization
depends on the serializer.
If you use the .toxml() method to serialize the document, you'll get
double quotes, I believe. It won't pretty-print though.
<?xml version="1.0"?><request xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNameSpaceSchemaLocation="Handle.xsd"/>
xml.dom.ext.Print and PrettyPrint haven't been updated in ages.
Well, they've been updated, but only in 4Suite (where they manifest as
Ft.Xml.Domlette.Print and PrettyPrint), not PyXML. In PyXML they're
hard-coded to use single quotes as attribute delimiters.
I asked on the list a while back if there was any interest in bringing
4Suite's Print/PrettyPrint implementation into PyXML and didn't get much
response. It's the kind of thing where if I want to see it done, I have to
> I use to create this one:
> dom = xml.dom.minidom.getDOMImplementation()
> doc = dom.createDocument(None, "request", None)
> #Get the document element
> msg_elem = doc.documentElement
> #Create an xmlns attributes on the root element
> msg_elem.setAttributeNS(EMPTY_NAMESPACE, "xmlns:xsi",
> msg_elem.setAttributeNS(EMPTY_NAMESPACE, "xsi:noNameSpaceSchemaLocation",
This isn't related to your quoting problem, but you are using the
wrong namespaces. Instead of EMPTY_NAMESPACE you need to do it like this:
msg_elem.setAttributeNS(XMLNS_NAMESPACE, 'xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance')
> 2. I want so post the above created xml structure to a webserver, but I
> need to convert this first to a string, how can I do this? PrettyPrint
> allows only writing this DOM structure to a file. Or is it possible to
> correctly read out this xml file?
A "file" in Python is any file-like object, basically anything with a .read()
and maybe also .write() method for byte strings. This includes the sys.stdin,
stdout, stderr streams.
So to pretty-print to the screen, you could just do
And to print to a buffer rather than an external file:
f = cStringIO.StringIO()
To read from that buffer into a string, s:
s = f.getvalue()
s = f.read()
To read from an external file:
f = open('yourfile', 'rb')
s = f.read()
Always be sure to call close() on your file-like objects when you're done
reading or writing to them. (though not really necessary on sys.stdin, stdout,
I don't know what web API you're using, but if you have access to an
object representing the HTTP request, it might have a method that
reads from a stream, in which case you could do something like
to print directly to into the request object.
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