From eed042fae5c4fac102a39ef1bae30530505b5f7f Mon Sep 17 00:00:00 2001
From: Brian Crowell <brian@fluggo.com>
Date: Mon, 15 Oct 2012 21:05:26 -0500
Subject: [PATCH] py3k: __nonzero__ is now __bool__

---
 PIL/ImageMath.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/PIL/ImageMath.py b/PIL/ImageMath.py
index a9a129b19..28dd254be 100644
--- a/PIL/ImageMath.py
+++ b/PIL/ImageMath.py
@@ -17,6 +17,7 @@
 
 import Image
 import _imagingmath
+import sys
 
 VERBOSE = 0
 
@@ -84,9 +85,15 @@ class _Operand:
         return _Operand(out)
 
     # unary operators
-    def __nonzero__(self):
-        # an image is "true" if it contains at least one non-zero pixel
-        return self.im.getbbox() is not None
+    if sys.version_info >= (3,0):
+        def __bool__(self):
+            # an image is "true" if it contains at least one non-zero pixel
+            return self.im.getbbox() is not None
+    else:
+        def __nonzero__(self):
+            # an image is "true" if it contains at least one non-zero pixel
+            return self.im.getbbox() is not None
+
     def __abs__(self):
         return self.apply("abs", self)
     def __pos__(self):