Rip out all the u"..." literals and calls to unicode().
diff --git a/Lib/encodings/punycode.py b/Lib/encodings/punycode.py
index 0e4aa0b..c86aad7 100644
--- a/Lib/encodings/punycode.py
+++ b/Lib/encodings/punycode.py
@@ -189,7 +189,7 @@
     else:
         base = text[:pos]
         extended = text[pos+1:]
-    base = unicode(base, "ascii", errors)
+    base = str(base, "ascii", errors)
     extended = extended.upper()
     return insertion_sort(base, extended, errors)