1 files changed, 12 insertions, 2 deletions
diff --git a/mako/util.py b/mako/util.py
index e279f5e..f6ef125 100644
--- a/mako/util.py
+++ b/mako/util.py
@@ -86,8 +86,18 @@ def to_list(x, default=None):
         return x
 
 
- 
-
+class memoized_property(object):
+    """A read-only @property that is only evaluated once."""
+    def __init__(self, fget, doc=None):
+        self.fget = fget
+        self.__doc__ = doc or fget.__doc__
+        self.__name__ = fget.__name__
+
+    def __get__(self, obj, cls):
+        if obj is None:
+            return self
+        obj.__dict__[self.__name__] = result = self.fget(obj)
+        return result
 
 class SetLikeDict(dict):
     """a dictionary that has some setlike methods on it"""