Ticket #19872: cached_property.patch

django/utils/functional.py

@@ -37 +37 @@
     def __init__(self, func):
         self.func = func
 
-    def __get__(self, instance, type):
+    def __get__(self, instance, type=None):
+        if instance is None:
+            return self
         res = instance.__dict__[self.func.__name__] = self.func(instance)
         return res