Avoid nested KeyError exception for threaded_cached_property

Author: spyoungtech

cached_property.py

@@ -68,10 +68,10 @@ def __get__(self, obj, cls):
             try:
                 # check if the value was computed before the lock was acquired
                 return obj_dict[name]
-
             except KeyError:
-                # if not, do the calculation and release the lock
-                return obj_dict.setdefault(name, self.func(obj))
+                pass
+            # if not, do the calculation and release the lock
+            return obj_dict.setdefault(name, self.func(obj))
 
 
 class cached_property_with_ttl(object):