On Mon, Jan 25, 2010 at 6:59 AM, Lennart Regebro <lrege...@jarn.com> wrote:
[snip]
> If class A returns NotImplemented when compared to class B, and class
> B implements the recipe above, then we get infinite recursion, because
>
> 1. A() < B() will call A.__lt__(B) which will return NotImplemented.
> 2. which will mean that Python calls B.__ge__(A)
> 3. Which B implements by doing A < B
> 4. Start over at 1.
A small correction; For the purposes of NotImplemented the opposite
of __lt__ is __gt__ because if A < B then B > A. The pairs are ('==',
'!='), ('<', '>'), ('<=', '>=').
-Jack
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