[Python-ideas] Assignment decorators (Re: The Descriptor Protocol...)

Ethan Furman ethan at stoneleaf.us
Fri Mar 4 00:13:37 CET 2011


Greg Ewing wrote:
> Ethan Furman wrote:
>> Greg Ewing wrote:
>>
>>> I think we should have assignment decorators.
>>>
>>> @decorator
>>> lhs = rhs
>>
>> That seems very verbose -- part of the issue for me is all the extra 
>> typing involved in specifying the name twice, and I don't think this 
>> is going to save many, if any, keystrokes.
> 
> I don't follow. It costs an @ and a newline, but it saves
> one instance of the name, plus two quotes, a comma and
> perhaps a space.

Ah -- I thought 'decorator' was a stand-in for an actual decorator name. 
  Still not in love with it though... an @ on a line all by itself? 
Ick.  (How's that for a reasoned argument? ;)


> Anyway, the main issue for me in violating DRY isn't the
> number of keystrokes. The main issues are:
> 
> * It's harder to read -- the repeated name is just noise
>   that doesn't convey any useful information to the reader.
> 
> * It's harder to maintain -- if you change the name, you
>   have to remember to change it in both places.

Yup, those are the main issues.  Didn't someone say that meta-classes 
can be used to solve this issue?

~Ethan~



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