diff --git a/pygal/graph/pie.py b/pygal/graph/pie.py
index 28505f9..e3a9104 100644
--- a/pygal/graph/pie.py
+++ b/pygal/graph/pie.py
@@ -32,7 +32,7 @@ class Pie(Graph):
     """Pie graph"""
 
     _adapters = [positive, none_to_zero]
-    
+
     @property
     def _format(self):
         """Return the value formatter for this graph"""