Rename buffer -> bytearray.
diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py
index 30f507a..c2ba1da 100644
--- a/Lib/encodings/idna.py
+++ b/Lib/encodings/idna.py
@@ -153,7 +153,7 @@
         if not input:
             return b'', 0
 
-        result = buffer()
+        result = bytearray()
         labels = dots.split(input)
         if labels and not labels[-1]:
             trailing_dot = b'.'
@@ -216,7 +216,7 @@
                 if labels:
                     trailing_dot = b'.'
 
-        result = buffer()
+        result = bytearray()
         size = 0
         for label in labels:
             if size: