id,summary,reporter,owner,description,type,status,priority,component,severity,resolution,keywords,cc
53,Allow for immutable subclasses of YAMLObject,toidinamai,xi,"YAMLObject are not directly instantiated so they don't need their own
instance attribute (i.e. an own dict). Because of that they should define
an empty __slots__ and let subclasses decide whether they want arbitrary
instance attributes or not:

{{{
--- lib/yaml/__init__.py        (revision 251)
+++ lib/yaml/__init__.py        (working copy)
@@ -272,6 +272,9 @@
     yaml_tag = None
     yaml_flow_style = None
 
+    # no direct instantiation, so allow for immutable subclasses
+    __slots__ = ()
+
     def from_yaml(cls, loader, node):
         """"""
         Convert a representation node to a Python object.
}}}

The same is basically also true for YAMLObjectMetaclass but I doubt there
is much use for this in practice.",enhancement,closed,normal,pyyaml,trivial,fixed,,