[Python-ideas] Keyword same in right hand side of assignments (rev)

Jacob Holm jh at improva.dk
Wed Mar 18 01:43:52 CET 2009

Steven D'Aprano wrote:
> One last question -- what should happen here?
> x, y, z = (same, same+1, same+2)

Obviously a typeerror, as you cannot add one or two to a tuple...  :)

But the same question for the statement

x, y, z = (same, foo(same), bar(same))

has a simple obvious anwer (at least to my eyes).  It should be 
equivalent to:

tmp = x, y, z
z, y, z = (tmp, foo(tmp), bar(tmp))

However, On rereading the proposal(s), I can see that all the operations 
using same are supposedly defined in terms of augmented assignment 
operators which really doesn't make any sense to me. (Augmented 
assignment is one of the very few things in python I find really 
unclean.  I know practicality beats purity and all that, but it just 
doesn't sit right with me).

It is quite possible that I have been interpreting this whole idea 
differently than the original author intended.  If so, I apologize for 
the confusion.  In any case I am at best -0.5 on it, because the benefit 
does not outweigh the cost of adding a new keyword.


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