id,summary,reporter,owner,description,type,status,priority,component,severity,resolution,keywords,cc
101,YAMLObject interacts poorly with __slots__,Joe Wreschnig,xi,"If I try to define a custom {{{__slots__}}} for a subclass of {{{YAMLObject}}} I get errors during serialization because the code tries to use {{{instance.__dict__.update}}}, but {{{__dict__}}} doesn't exist on objects with slots.

{{{
  File ""/usr/lib/python2.4/site-packages/yaml/__init__.py"", line 177, in dump
    return dump_all([data], stream, Dumper=Dumper, **kwds)
  File ""/usr/lib/python2.4/site-packages/yaml/__init__.py"", line 167, in dump_all
    dumper.represent(data)
  File ""/usr/lib/python2.4/site-packages/yaml/representer.py"", line 33, in represent
    node = self.represent_data(data)
  File ""/usr/lib/python2.4/site-packages/yaml/representer.py"", line 62, in represent_data
    node = self.yaml_representers[data_types[0]](self, data)
  File ""/home/piman/code/layer/layer/parse.py"", line 84, in __to_yaml
    return dumper.represent_yaml_object(
  File ""/usr/lib/python2.4/site-packages/yaml/representer.py"", line 248, in represent_yaml_object
    state = data.__dict__.copy()
AttributeError: 'NPoint' object has no attribute '__dict__'
}}}

Attached is a patch that makes the constructor use {{{setattr}}} and the representer use {{{__slots__}}} if {{{__dict__}}} is not available. I did not write unit tests, as I couldn't figure out how to run them, but it makes the unit tests for my own project (which uses {{{__slots__}}} for some objects and {{{__dict__}}} for others) pass.",defect,new,normal,pyyaml,normal,,,