diff --git a/Lib/difflib.py b/Lib/difflib.py
index 7ab682d..408079b 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -652,8 +652,7 @@
         1.0
         """
 
-        matches = reduce(lambda sum, triple: sum + triple[-1],
-                         self.get_matching_blocks(), 0)
+        matches = sum(triple[-1] for triple in self.get_matching_blocks())
         return _calculate_ratio(matches, len(self.a) + len(self.b))
 
     def quick_ratio(self):