Classes as namespaces?

J. Clifford Dyer jcd at sdf.lonestar.org
Sat Mar 27 12:54:06 CET 2010


On Sat, Mar 27, 2010 at 04:28:56AM -0700, Jonathan Hartley wrote regarding Re: Classes as namespaces?:
> 
> Hey everyone. By coincidence, only yesterday I was wondering about
> using classes as a way of labeling a block of code, ie. an lightweight
> alternative to defining a function that would only be called from one
> location.
> 
> eg. instead of:
> 
> 
> x = 1
> ((some complex logic))
> y = 2
> 
> 
> one might like to name the complex block of logic, just to make it
> readable:
> 
> 
> x = 1
> def account_for_non_square_pixels(x):
>    ((some complex logic))
> account_for_non_square_pixels()
> y = 2
> 
> 
> But defining and then calling the function like that is a tad
> cumbersome. So I was wondering about:
> 
> 
> 
> x = 1
> class account_for_non_square_pixels:
>   ((some complex logic))
> y = 2
> 
> 
> I don't exactly like this, but I think you can see what I'm getting
> at. Does this fall down in some way I haven't grasped? Is it as awful
> an abuse of 'class' as my intuition suggests it is? Is there a way to
> do it better?
> -- 
> http://mail.python.org/mailman/listinfo/python-list

Hmm.  I don't like that because it leaves a class polluting your namespace that doesn't behave like a class.  Using a function for that purpose doesn't seem as bad, because even if you don't call it again, at least you *could*, and it would behave in an expected fashion.  

If you're dead-set against calling the chunk of code you just created, and you're using python 2.5 or higher, you might consider creating a no-op context manager:

    x = 1
    with code_block("Account for non square pixels"):
	    ((complex_logic))
	y = 2

Though in general, I think refactoring your code to reasonably scoped functions or methods is a better idea.  If it's too complex to read in one block, it's probably too complex for one function.



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