Python parse XML ElementTree with namespace and attributes

#!/usr/bin/python
# -*- coding: utf-8 -*-

from sys import argv
import xml.etree.ElementTree as ET

NS = 'x' # default namespace key # (any string is OK)

class XMLParser(object):
    def __init__(self):
        self.ns = {}     # namespace dict
        self.root = None # XML's root element

    # extracts the namespace (usually from the root element)
    def get_namespace(self, tag):
        return tag.split('}')[0][1:]

    # loads the XML file (here: from string)
    def load_xml(self, xmlstring):
        root = ET.fromstring(xmlstring)
        self.root = root
        self.ns[NS] = self.get_namespace(root.tag)
        return True

    # transforms XPath without namespaces to XPath with namespace
    # AND detects if last element is an attribute
    def ns_xpath(self, xpath):
        tags = xpath.split('/')
        if tags[-1].startswith('@'):
            attrib = tags.pop()[1:]
        else:
            attrib = None
        nsxpath = '/'.join(['%s:%s' % (NS, tag) for tag in tags])
        return nsxpath, attrib

    # `find` and `findall` method in one place honoring attributes in XPath
    def xfind(self, xpath, e=None, findall=False):
        if not e:
            e = self.root
        if not findall:
            f = e.find
        else:
            f = e.findall
        nsxpath, attrib = self.ns_xpath(xpath)
        e = f(nsxpath, self.ns)
        if attrib:
            return e.get(attrib)
        return e

def main(xmlstring):
    p = XMLParser()
    p.load_xml(xmlstring)
    xpaths = {
        'Element a:': 'a',
        'Element b:': 'a/b',
        'Attribute c:': 'a/b/@c'
        }
    for key, xpath in xpaths.items():
        print key, xpath, p.xfind(xpath)

if __name__ == "__main__":
    xmlstring = """<root xmlns="http://www.example.com">
        <a>
            <b c="Hello, world!">
            </b>
        </a>
    </root>"""
    main(xmlstring)