On Sat, Apr 24, 2010 at 8:54 AM, Steven D'Aprano <st...@remove-this-cybersource.com.au> wrote: > I'm reading the source code for decimal.Decimal, and I see that the > arithmetic operations (__add__, __sub__, etc.) start with code like this: > > if other is NotImplemented: > return other > > > I don't understand the purpose of this. I presume that it is *not* for > the use-case of: > > d = Decimal('123.456') > result = d + NotImplemented > > which not only doesn't make sense to me, but when I try it, it raises > TypeError. So I find myself confused why the arithmetic methods do this. >
There's a _convert_other method which is called before the test that can return NotImplemented. -- regards, kushal -- http://mail.python.org/mailman/listinfo/python-list