optimize iterbytes on Python 2 (fixes #97)

Suggested by Wouter Bolsterlee.

2 files changed, 4 insertions, 2 deletions

diff --git a/CHANGES b/CHANGES
index 02a20f0..fa74e77 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,8 @@ This file lists the changes in each six version.
 Development version
 -------------------
 
+- Issue #97: Optimize `six.iterbytes` on Python 2.
+
 - Issue #98: Fix `six.moves` race condition in multi-threaded code.
 
 - Pull request #51: Add `six.view(keys|values|itmes)`, which provide dictionary
diff --git a/six.py b/six.py
index 0df4538..232a0c7 100644
--- a/six.py
+++ b/six.py
@@ -23,6 +23,7 @@
 from __future__ import absolute_import
 
 import functools
+import itertools
 import operator
 import sys
 import types
@@ -621,8 +622,7 @@ else:
         return ord(bs[0])
     def indexbytes(buf, i):
         return ord(buf[i])
-    def iterbytes(buf):
-        return (ord(byte) for byte in buf)
+    iterbytes = functools.partial(itertools.imap, ord)
     import StringIO
     StringIO = BytesIO = StringIO.StringIO
 _add_doc(b, """Byte literal""")