[Python-Dev] Equality testing

[Benjamin Peterson]

2011/5/18 Ethan Furman <ethan at stoneleaf.us>:
> In Python 3 inequality comparisons became forbidden.
>
> --> 123 < [1, 2, 3]
> Traceback (most recent call last):
>  File "<stdin>", line 1, in <module>
> TypeError: unorderable types: int() < list()
>
> However, equality comparisons are still allowed
>
> --> 123 == [1, 2, 3]
> False
>
> But you can't mix them (inequality wins)
>
> --> 123 <= [1, 2, 3]
> Traceback (most recent call last):
>  File "<stdin>", line 1, in <module>
> TypeError: unorderable types: int() <= list()
>
> I realize this is probably a Py4000 change if it happens at all, but does
> this make sense?  Shouldn't an attempt to compare to unlike objects be a
> TypeError, just like trying to order them is?

No. Ordering for types which completely different doesn't make any
sense, but equality testing is just fine because it has an obvious
answer: no.



-- 
Regards,
Benjamin