On 04/25/2013 05:27 PM, Steven D'Aprano wrote:
> On 26/04/13 09:56, MRAB wrote:
>> On the other hand:
>>>> type(value)(value) == value
>>>> would return True for the built-in types (will certain exceptions, such
>> as when value is float("NaN")).
>> Not an exception, that works fine in 3.3:
>>>>> value = float('nan')
>>>> type(value)(value)
> nan
You missed the == part:
>>> type(value)(value) == value
False
>> Let's ask the Zen:
>>>> Special cases aren't special enough to break the rules.
>>>> Although practicality beats purity.
>>> I cannot think of any use-case where I would actively want
> NoneType(None) to fail. That would be like having bool(True)
> raise an exception.
>> On the other hand, NoneType(x) for any other x ought to fail.
Or, since the purpose of NoneType is to return None, just return None no matter what!
Kind'a like 0 * anything == 0.
--
~Ethan~
