Creating a doctype with lxml's etree

Question

I want to add doctypes to my XML documents that I'm generating with LXML's etree.

However I cannot figure out how to add a doctype. Hardcoding and concating the string is not an option.

I was expecting something along the lines of how PI's are added in etree:

pi = etree.PI(...)
doc.addprevious(pi)

But it's not working for me. How to add a to a xml document with lxml?

Solution 1

This worked for me:

print etree.tostring(tree, pretty_print=True, xml_declaration=True, encoding="UTF-8", doctype="<!DOCTYPE TEST_FILE>")

Solution 2

The PI is actually added as a previous element from "doc". Thus, it's not a child of "doc". You must use "doc.getroottree()"

Here is an example:

>>> root = etree.Element("root")
>>> a  = etree.SubElement(root, "a")
>>> b = etree.SubElement(root, "b")
>>> root.addprevious(etree.PI('xml-stylesheet', 'type="text/xsl" href="my.xsl"'))
>>> print etree.tostring(root, pretty_print=True, xml_declaration=True, encoding='utf-8')
<?xml version='1.0' encoding='utf-8'?>
<root>
  <a/>
  <b/>
</root>

with getroottree():

>>> print etree.tostring(root.getroottree(), pretty_print=True, xml_declaration=True, encoding='utf-8')
<?xml version='1.0' encoding='utf-8'?>
<?xml-stylesheet type="text/xsl" href="my.xsl"?>
<root>
  <a/>
  <b/>
</root>