Don't use range for performance reasons

mrjoes · mrjoes · commit 78d9cc6519f2 · 2013-04-14T00:02:49.000+03:00
diff --git a/tornado/stack_context.py b/tornado/stack_context.py
@@ -259,8 +259,9 @@ def wrapped(*args, **kwargs):
                 exc = _handle_exception(top, exc)
             else:
                 # Otherwise take shorter path and run stack contexts in reverse order
-                for n in range(last_ctx - 1, -1, -1):
-                    c = stack[n]
+                while last_ctx > 0:
+                    last_ctx -= 1
+                    c = stack[last_ctx]
 
                     try:
                         c.exit(*exc)
