Accessing XMLNS attribute with Python Elementree?

Question

How can one access NS attributes through using ElementTree?

With the following:

Answer 1

Look at the effbot namespaces documentation/examples; specifically the parse_map function. It shows you how to add an *ns_map* attribute to each element which contains the prefix/URI mapping that applies to that specific element.

However, that adds the ns_map attribute to all the elements. For my needs, I found I wanted a global map of all the namespaces used to make element look up easier and not hardcoded.

Here's what I came up with:

import elementtree.ElementTree as ET

def parse_and_get_ns(file):
    events = "start", "start-ns"
    root = None
    ns = {}
    for event, elem in ET.iterparse(file, events):
        if event == "start-ns":
            if elem[0] in ns and ns[elem[0]] != elem[1]:
                # NOTE: It is perfectly valid to have the same prefix refer
                #     to different URI namespaces in different parts of the
                #     document. This exception serves as a reminder that this
                #     solution is not robust.    Use at your own peril.
                raise KeyError("Duplicate prefix with different URI found.")
            ns[elem[0]] = "{%s}" % elem[1]
        elif event == "start":
            if root is None:
                root = elem
    return ET.ElementTree(root), ns

With this you can parse an xml file and obtain a dict with the namespace mappings. So, if you have an xml file like the following ("my.xml"):

  
    
    Joe McGroin
    etc...
  

You will be able to use the xml namepaces and get info for elements like dc:creator:

>>> tree, ns = parse_and_get_ns("my.xml")
>>> ns
{u'content': '{http://purl.org/rss/1.0/modules/content/}',
u'dc': '{http://purl.org/dc/elements/1.1/}'}
>>> item = tree.find("/feed/item")
>>> item.findtext(ns['dc']+"creator")
'Joe McGroin'