Python ElementTree module: How to ignore the namespace of XML files to locate matching element when using the method "find", "findall"

Question

Instead of modifying the XML document itself, it's best to parse it and then modify the tags in the result. This way you can handle multiple namespaces and namespace aliases:

from io import StringIO  # for Python 2 import from StringIO instead
import xml.etree.ElementTree as ET

# instead of ET.fromstring(xml)
it = ET.iterparse(StringIO(xml))
for _, el in it:
    prefix, has_namespace, postfix = el.tag.partition('}')
    if has_namespace:
        el.tag = postfix  # strip all namespaces
root = it.root

This is based on the discussion here: http://bugs.python.org/issue18304

Update: rpartition instead of partition makes sure you get the tag name in postfix even if there is no namespace. Thus you could condense it:

for _, el in it:
    _, _, el.tag = el.tag.rpartition('}') # strip ns

If you remove the xmlns attribute from the xml before parsing it then there won't be a namespace prepended to each tag in the tree.

import re

xmlstring = re.sub(' xmlns="[^"]+"', '', xmlstring, count=1)

The answers so far explicitely put the namespace value in the script. For a more generic solution, I would rather extract the namespace from the xml:

import re
def get_namespace(element):
  m = re.match('\{.*\}', element.tag)
  return m.group(0) if m else ''

And use it in find method:

namespace = get_namespace(tree.getroot())
print tree.find('./{0}parent/{0}version'.format(namespace)).text

Here's an extension to @nonagon answer (which removes namespace from tags) to also remove namespace from attributes:

import io
import xml.etree.ElementTree as ET

# instead of ET.fromstring(xml)
it = ET.iterparse(io.StringIO(xml))
for _, el in it:
    if '}' in el.tag:
        el.tag = el.tag.split('}', 1)[1]  # strip all namespaces
    for at in list(el.attrib.keys()): # strip namespaces of attributes too
        if '}' in at:
            newat = at.split('}', 1)[1]
            el.attrib[newat] = el.attrib[at]
            del el.attrib[at]
root = it.root

Obviously this is a permanent defacing of the XML but if that's acceptable because there are no non-unique tag names and because you won't be writing the file needing the original namespaces then this can make accessing it a lot easier

Improving on the answer by ericspod:

Instead of changing the parse mode globally we can wrap this in an object supporting the with construct.

from xml.parsers import expat

class DisableXmlNamespaces:
    def __enter__(self):
            self.oldcreate = expat.ParserCreate
            expat.ParserCreate = lambda encoding, sep: self.oldcreate(encoding, None)
    def __exit__(self, type, value, traceback):
            expat.ParserCreate = self.oldcreate

This can then be used as follows

import xml.etree.ElementTree as ET
with DisableXmlNamespaces():
     tree = ET.parse("test.xml")

The beauty of this way is that it does not change any behaviour for unrelated code outside the with block. I ended up creating this after getting errors in unrelated libraries after using the version by ericspod which also happened to use expat.