On 01.06.2011 10:26, Carl M. Johnson wrote:
On Tue, May 31, 2011 at 9:05 PM, Georg Brandl <g.brandl@gmx.net <mailto:g.brandl@gmx.net>> wrote:
Sure, this can only work if the local is assigned somewhere before the augmented assign statement. But this is just like accessing a local before its assignment: in the case of
x = 1 def f(): print x x = 2
we also don't treat the first "x" reference as a nonlocal.
I don't think that's a counterexample to the point I'm trying to make. We all agree that if there's an x= somewhere in the function body, then we have to treat the variable as a local. The only possible way around that would be to solve the halting problem in order to figure out if a particular line of code will be reached or not. Agreed, sure, we have to treat the LHS of = as a local. But += is fundamentally different.
You keep saying that, but I just can't see how += is fundamentally different from =, given its definition as x = x.__iadd__(y). This is a situation that comes up from time to time, where it seems logical to make a change that satisfies "DWIM" feelings, but makes the languge more inconsistent by introducing special cases. This doesn't feel right to me (and the Zen agrees ;) Georg