[MERGE] versionedfile.py code cleanups

[Michael Hudson]

On 20 Sep 2007, at 6:21, Martin Pool wrote:

> On 9/20/07, Robert Collins <robertc at robertcollins.net> wrote:
>
>> Well, I think you've made a generalisation of LBYL that is slightly
>> different to its normal meaning, which is about not running code to
>> check things that will be handled in due course. Specifically this  
>> stub
>> method does not introduce race conditions that LBYL do, nor waste CPU
>> time checking things that are checked later anyway etc.
>
> It's academic because I think it's reasonable to provide a docstring
> for pure virtual methods, and in Python that means they must have a
> body which should be a raise statement.  (Or maybe epydoc has a
> special way to handle this?)

Eh, no?  A docstring is a function body, for this purpose.

Raising an exception is still a good idea, of course.

Cheers,
mwh