Use iterator-based range instead of a list-based range for buffer filling

svartalf · svartalf · commit ba7839201dcf · 2012-05-25T16:43:38.000+09:00
diff --git a/quirc/base.py b/quirc/base.py
@@ -66,6 +66,9 @@ def __init__(self, width, height):
         self._width = width
         self._height = height
 
+        self._width_iter = compat.range(self._width)
+        self._height_iter = compat.range(self._height)
+
         self._obj = api.new()
         api.resize(self._obj, self._width, self._height)
 
@@ -80,8 +83,8 @@ def decode(self, image):
         pixels = image.load()
 
         idx = 0
-        for i in range(self._width):
-            for j in range(self._height):
+        for i in self._width_iter:
+            for j in self._height_iter:
                 buffer[idx] = ctypes.c_uint8(pixels[j, i])
                 idx += 1
 
diff --git a/quirc/compat.py b/quirc/compat.py
@@ -2,6 +2,11 @@
 
 """Miscellaneous compatibility checks"""
 
+import sys
+
+
+range = range if sys.version_info[0] == 3 else xrange
+
 # Image libraries
 have_pil = True
 try:
diff --git a/quirc/converters.py b/quirc/converters.py
@@ -7,6 +7,8 @@
 
 import ctypes
 
+from compat import range
+
 
 def pil(image):
     """Convert the PIL.Image object to the pixels buffer
@@ -21,6 +23,9 @@ def pil(image):
 
     pixels = image.load()
 
-    for i in range(width):
-        for j in range(height):
+    width_iter = range(width)
+    height_iter = range(height)
+
+    for i in width_iter:
+        for j in height_iter:
             yield ctypes.c_uint8(pixels[j, i])
