Try to fix missing register_namespace in python 2.6

demo/moulinrouge/__init__.py

@@ -16,11 +16,12 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with pygal. If not, see <http://www.gnu.org/licenses/>.
-from flask import Flask, render_template, Response
+from flask import Flask, render_template, Response, request
 import pygal
 from pygal.config import Config
 from pygal.util import cut
 from pygal.graph import CHARTS_NAMES
+from pygal.etree import etree
 from pygal.style import styles, parametric_styles
 from base64 import (
     urlsafe_b64encode as b64encode,
@@ -46,6 +47,13 @@ def create_app():
 
     app = Flask(__name__)
 
+    @app.before_request
+    def before_request():
+        if request.args.get('etree'):
+            etree.to_etree()
+        else:
+            etree.to_lxml()
+
     def _random(data, order):
         max = 10 ** order
         min = 10 ** random.randrange(0, order)

pygal/svg.py

@@ -59,7 +59,10 @@ class Svg(object):
             attrs = {
                 'xmlns': self.ns
             }
-            etree.register_namespace('xlink', self.xlink_ns)
+            if hasattr(etree, 'register_namespace'):
+                etree.register_namespace('xlink', self.xlink_ns)
+            else:
+                etree._namespace_map[self.xlink_ns] = 'xlink'
 
         self.root = etree.Element('svg', **attrs)
         self.root.attrib['id'] = self.id.lstrip('#').rstrip()
@@ -150,7 +153,8 @@ class Svg(object):
                 attrib[key.rstrip('_')] = attrib[key]
                 del attrib[key]
             elif key == 'href':
-                attrib['{http://www.w3.org/1999/xlink}' + key] = attrib[key]
+                attrib[etree.QName(
+                    'http://www.w3.org/1999/xlink',  key)] = attrib[key]
                 del attrib[key]
         return etree.SubElement(parent, tag, attrib)