On Sat, 24 Apr 2010 09:05:14 +0530, Kushal Kumaran wrote: > 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.
Yes, I can see that, but why? -- Steven -- http://mail.python.org/mailman/listinfo/python-list