python - how to get a list of inner classes?

Question

I'm writing a small Python application that contains a few nested classes, like the example below:

class SuperBar(object):
    pass

class Foo(object):
    NAME = 'this is foo'

    class Bar(SuperBar):
        MSG = 'this is how Bar handle stuff'

    class AnotherBar(SuperBar):
        MSG = 'this is how Another Bar handle stuff'

I'm using nested classes to create some sort of hierarchy and to provide a clean way to implement features for a parser.

At some point, I want to create a list of the inner classes. I'd like to have the following output:

[<class '__main__.Bar'>, <class '__main__.AnotherBar'>]

The question is: What is the recommended method to get a list of inner classes in a pythonic way?

Answer 1

I managed to get a list of inner class objects with the method below:

import inspect

def inner_classes_list(cls):
    return [cls_attribute for cls_attribute in cls.__dict__.values()
            if inspect.isclass(cls_attribute)
            and issubclass(cls_attribute, SuperBar)]

It works, but I'm not sure if using __dict__ directly is a good thing to do. I'm using it because it contains the actual class instances that I need and seems to be portable across Python 2 and 3.