Python Cookbook

Transforming an XML Document Using XSLT

Credit: David Ascher

Problem

You have an XSLT transform that you wish to programmatically run through XML documents.

Solution

The solution depends on the XSLT processor you’re using. If you’re using Microsoft’s XSLT engine (part of its XML Core Services package), you can drive the XSLT engine through its COM interface:

def process_with_msxslt(xsltfname, xmlfname, targetfname):
    import win32com.client.dynamic
    xslt = win32com.client.dynamic.Dispatch("Msxml2.DOMDocument.4.0")
    xslt.async = 0
    xslt.load(xsltfname)
    xml = win32com.client.dynamic.Dispatch("Msxml2.DOMDocument.4.0")
    xml.async = 0
    xml.load(xmlfname)
    output = xml.transformNode(xslt)
    open(targetfname, 'wb').write(output)

If you’d rather use Xalan’s XSLT engine, it’s as simple as using the right module:

import Pyana
output = Pyana.transform2String(source=open(xmlfname).read(  ),
                                style=open(xsltfname).read(  ))
open(targetfname, 'wb').write(output)

Discussion

There are many different ways that XML documents need to be processed. Extensible Stylesheet Language Transformations (XSLT) is a language that was developed specifically for transforming XML documents. Using XSLT, you define a stylesheet, which is a set of templates and rules that defines how to transform specific parts of an XML document into arbitrary outputs.

The XSLT specification is a World Wide Web Consortium Recommendation (http://www.w3.org/TR/xslt) that has been implemented by many different organizations. The two most commonly used ...