use str as variable name

[Fredrik Lundh]

Marco Bizzarri wrote:

>> (...as Bruno implies, setattr(), len() et al can be and should be viewed as
>> generic functions.
> 
> Just a question: "generic functions" are not meant in the sense of
> "generic functions" of CLOS, am I right?

it's meant in exactly that sense: len(L) means "of all len() 
implementations available to the runtime, execute the most specific code 
we have for the object L".

</F>