Index: saxutils.py
===================================================================
--- saxutils.py	(revision 74182)
+++ saxutils.py	(working copy)
@@ -83,10 +83,7 @@
 
 class XMLGenerator(handler.ContentHandler):
 
-    def __init__(self, out=None, encoding="iso-8859-1"):
-        if out is None:
-            import sys
-            out = sys.stdout
+    def __init__(self, out, encoding="iso-8859-1"):
         handler.ContentHandler.__init__(self)
         self._out = out
         self._ns_contexts = [{}] # contains uri -> prefix dicts
@@ -95,10 +92,7 @@
         self._encoding = encoding
 
     def _write(self, text):
-        if isinstance(text, str):
-            self._out.write(text)
-        else:
-            self._out.write(text.encode(self._encoding, _error_handling))
+        self._out.write(text.encode(self._encoding, _error_handling))
 
     def _qname(self, name):
         """Builds a qualified name from a (ns_url, localname) pair"""
@@ -140,9 +134,9 @@
 
         for prefix, uri in self._undeclared_ns_maps:
             if prefix:
-                self._out.write(' xmlns:%s="%s"' % (prefix, uri))
+                self._write(' xmlns:%s="%s"' % (prefix, uri))
             else:
-                self._out.write(' xmlns="%s"' % uri)
+                self._write(' xmlns="%s"' % uri)
         self._undeclared_ns_maps = []
 
         for (name, value) in attrs.items():