[Python-Dev] PEP for Better Control of Nested Lexical Scopes

Ian Bicking ianb at colorstudy.com
Tue Feb 21 22:13:22 CET 2006


Mark Russell wrote:
> On 21 Feb 2006, at 19:25, Jeremy Hylton wrote:
> 
>>If I recall the discussion correctly, Guido said he was open to a
>>version of nested scopes that allowed rebinding.
> 
> 
> PEP 227 mentions using := as a rebinding operator, but rejects the  
> idea as it would encourage the use of closures.  But to me it seems  
> more elegant than some special keyword, especially is it could also  
> replace the "global" keyword.  It doesn't handle things like "x += y"  
> but I think you could deal with that by just writing "x := x + y".

By rebinding operator, does that mean it is actually an operator?  I.e.:

   # Required assignment to declare?:
   chunk = None
   while chunk := f.read(1000):
       ...


-- 
Ian Bicking  /  ianb at colorstudy.com  /  http://blog.ianbicking.org


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