A TYPICAL NEWBIE MISTAKE?

[Frank V. Castellucci]

François Pinard wrote:
> 
> Courageous <jkraska1 at san.rr.com> writes:
> 
> > My key point was that it's easy to get confused when assignment to
> > self.attribute overrides the common class attribute. [...]
> 
> The question was surely interesting.  In any case, from my own experience, I
> found out that common class attributes (besides the class methods themselves)
> are not much used in practice.  There are only three cases where I found
> them useful:
> 
> * To get speedier __init__ by presetting some slow-to-compute parameters,
>   when these are independent of actual __init__ parameters, since the
>   computation occurs once when the class gets defined.
> 
> * To build overall dictionaries or list of all instances of a class, by
>   presetting the dictionary to empty as a common attribute, and having each
>   __init__ to register the newly created instance to that dictionary.
> 
> * To ease the writing and access of some dictionaries, using classes usually
>   having no methods; my favourite is a `run' class which holds all the global
>   option values, and nothing else, which I preset with default option values.
> 
> --
> François Pinard   http://www.iro.umontreal.ca/~pinard

Add to that instrumentation, singleton objects, and framework handlers.

-- 
Frank V. Castellucci
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