__bases__ misleading error message

[Mario Figueiredo]

In article <54c4dae1$0$13005$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> [...]

Most excellent. Thanks for the hard work, explaining this to me. :)

Knowing Python internals is something that will end benefiting me in the 
long run. There's much to be gained by knowing the inner working of your 
programming language...

Python is missing an under-the-hood book, I suppose. Tracing through 
Python source code to learn this stuff isn't easy unless we know what we 
are looking for.