numpydoc for theano/gof/null_type.py

theano/gof/null_type.py

@@ -3,19 +3,21 @@ from theano.gof.type import Type
 
 class NullType(Type):
     """
+    A type that allows no values.
 
-    A type that allows no values. Used to represent expressions
+    Used to represent expressions
     that are undefined, either because they do not exist mathematically
     or because the code to generate the expression has not been
     implemented yet.
 
+    Parameters
+    ----------
+    why_null : str
+        A string explaining why this variable can't take on any values.
+
     """
 
     def __init__(self, why_null='(no explanation given)'):
-        """
-            why_null: A string explaining why this variable
-                    can't take on any values
-        """
         self.why_null = why_null
 
     def filter(self, data, strict=False, allow_downcast=None):