When I use Sphinx autodoc to document a class, the values for the attributes are always reported, (as it says it should here, under #437) but always as "= None"
Attribute = None
.. autoclass:: core.SomeClass
self.attribute = "value" #: Some Documentation
I am pretty sure this has to do with the fact that your attribute is an instance attribute. It does not get a value until the class is instantiated. Sphinx imports modules in order to inspect them, but it does not instantiate any classes.
So the "real value" is not known by Sphinx, and
None is output. I don't think you can make it go away easily (but I suppose anything is possible if you are prepared to patch the Sphinx source code...). If you don't like this, you could document attributes in the docstring of the class instead.
Class attributes that are documented using the same markup scheme (described here) do get their values displayed in the rendered output. But there is no clear indication that makes it easy for the reader to distinguish between class and instance attributes. Maybe Sphinx could be a little more helpful here.