[Python-Dev] Python-Dev Digest, Vol 69, Issue 143

[Greg Ewing]

Steven D'Aprano wrote:
> it should be obvious in the 
> same way that string concatenation is different from numerical 
> addition:
> 
> 1 + 2 = 2 + 1
> '1' + '2' != '2' + '1'

However, the proposed arithmetic isn't just non-
commutative, it's non-associative, which is a
much rarer and more surprising thing. We do
at least have

   ('1' + '2') + '3' == '1' + ('2' + '3')

-- 
Greg