C-style static variables in Python?

Ethan Furman ethan at stoneleaf.us
Fri Apr 2 21:38:56 CEST 2010


Patrick Maupin wrote:
> On Apr 2, 1:21 pm, Ethan Furman <et... at stoneleaf.us> wrote:
>> For this type of situation, my preference would be:
>>
>> class spam(object):
>>      def __call__(self, x, y, z):
>>          try:
>>              mongo = self.mongo
>>          except AttributeError:
>>              mongo = self.mongo = heavy_lifting_at_runtime()
>>          return frobnicate(x, y, z, mongo)
>> spam = spam()
>>
>> No extra objects, out-of-place underscores, etc.
>>
>> ~Ethan~
> 
> Well, I'm not a big fan of unnecessary try/except, so I would at least
> change it to:
> 
> class spam(object):
>      def __getattr__(self, name):
>          if name != 'mongo':
>              raise AttributeError
>          self.mongo = heavy_lifting_at_runtime()
>          return self.mongo
>      def __call__(self, x, y, z):
>          return frobnicate(x, y, z, self.mongo)
> spam = spam()
> 
> Regards,
> Pat


Sounds like a personal preference issue, rather than a necessary / 
unnecessary issue -- after all, if you call that function a thousand 
times, only once is mongo not defined... clearly the exception.  ;)

~Ethan~



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