Index: twisted/words/xish/domish.py
===================================================================
--- twisted/words/xish/domish.py	(revision 4949)
+++ twisted/words/xish/domish.py	(working copy)
@@ -5,7 +5,7 @@
 
 from __future__ import generators
 
-import types
+from types import StringTypes, TupleType
 
 from zope.interface import implements, Interface, Attribute
 
@@ -49,8 +49,8 @@
         return False
 
     def serialize(self, elem, closeElement=1, defaultUri=''):
-        # Optimization shortcuts
-        write = self.writelist.append
+	# Optimization shortcuts
+	write = self.writelist.append
 
         # Shortcut, check to see if elem is actually a chunk o' serialized XML
         if isinstance(elem, SerializedXML):
@@ -58,7 +58,7 @@
             return
 
         # Shortcut, check to see if elem is actually a string (aka Cdata)
-        if isinstance(elem, types.StringTypes):
+        if isinstance(elem, StringTypes):
             write(escapeToXml(elem))
             return
 
@@ -79,45 +79,70 @@
         if uri is None:
             uri = defaultUri
 
-        prefix = None
+	prefix = None
         if uri != defaultUri or uri in self.prefixes:
             prefix = self.getPrefix(uri)
             inScope = self.prefixInScope(prefix)
 
         # Create the starttag
-
+	write("<")
         if not prefix:
-            write("<%s" % (name))
-        else:
-            write("<%s:%s" % (prefix, name))
+	    write(name)
+	else:
+	    write(prefix)
+	    write(":")
+	    write(name)
 
             if not inScope:
-                write(" xmlns:%s='%s'" % (prefix, uri))
+		write(" xmlns:")
+		write(prefix)
+		write("='")
+		write(uri)
+		write("'")
                 self.prefixStack[-1].append(prefix)
                 inScope = True
 
         if defaultUri != currentDefaultUri and \
            (uri != defaultUri or not prefix or not inScope):
-            write(" xmlns='%s'" % (defaultUri))
+	    write(" xmlns='")
+	    write(defaultUri)
+	    write("'")
 
         for p, u in elem.localPrefixes.iteritems():
-            write(" xmlns:%s='%s'" % (p, u))
+	    write(" xmlns:")
+	    write(p)
+	    write("='")
+	    write(u)
+	    write("'")
 
         # Serialize attributes
-        for k,v in elem.attributes.items():
+        for k, v in elem.attributes.items():
             # If the attribute name is a tuple, it's a qualified attribute
-            if isinstance(k, types.TupleType):
+            if isinstance(k, TupleType):
                 attr_uri, attr_name = k
                 attr_prefix = self.getPrefix(attr_uri)
 
                 if not self.prefixInScope(attr_prefix):
-                    write(" xmlns:%s='%s'" % (attr_prefix, attr_uri))
-                    self.prefixStack[-1].append(attr_prefix)
+		    write(" xmlns:")
+		    write(attr_prefix)
+		    write("='")
+		    write(attr_uri)
+		    write("'")
+		    self.prefixStack[-1].append(attr_prefix)
 
-                write(" %s:%s='%s'" % (attr_prefix, attr_name,
-                                       escapeToXml(v, 1)))
+		write(" ")
+		write(attr_prefix)
+		write(":")
+		write(attr_name)
+		write("='")
+		write(escapeToXml(v, 1))
+		write("'")
             else:
-                write((" %s='%s'" % ( k, escapeToXml(v, 1))))
+		write(" ")
+		write(k)
+		write("='")
+		write(escapeToXml(v, 1))
+		write("'")
 
         # Shortcut out if this is only going to return
         # the element (i.e. no children)
@@ -128,19 +153,20 @@
         # Serialize children
         if len(elem.children) > 0:
             write(">")
-            for c in elem.children:
-                self.serialize(c, defaultUri=defaultUri)
+	    for c in elem.children:
+		self.serialize(c, defaultUri=defaultUri)
             # Add closing tag
-            if not prefix:
-                write("</%s>" % (name))
-            else:
-                write("</%s:%s>" % (prefix, name))
+	    write("</")
+	    if prefix:
+		write(prefix)
+		write(":")
+	    write(name)
+	    write(">")
         else:
             write("/>")
 
         self.prefixStack.pop()
 
-
 SerializerClass = _ListSerializer
 
 def escapeToXml(text, isattrib = 0):
@@ -428,12 +454,12 @@
         """ Retrieve the first CData (content) node 
         """
         for n in self.children:
-            if isinstance(n, types.StringTypes): return n
+            if isinstance(n, StringTypes): return n
         return ""
 
     def _dqa(self, attr):
         """ Dequalify an attribute key as needed """
-        if isinstance(attr, types.TupleType) and not attr[0]:
+        if isinstance(attr, TupleType) and not attr[0]:
             return attr[1]
         else:
             return attr
@@ -470,7 +496,7 @@
     def addContent(self, text):
         """ Add some text data to this Element. """
         c = self.children
-        if len(c) > 0 and isinstance(c[-1], types.StringTypes):
+        if len(c) > 0 and isinstance(c[-1], StringTypes):
             c[-1] = c[-1] + text
         else:
             c.append(text)