Everything is an object in python - object class and type class

[Mark Lawrence]

On 03/06/2015 17:00, BartC wrote:
> On 03/06/2015 13:08, Marko Rauhamaa wrote:
>> BartC <bc at freeuk.com>:
>>
>>> To 'variable' and 'type', you might need to add 'value' to make it more
>>> complete.
>>
>> 'Value' and 'object' are indeed synonymous as long as you keep in mind
>> that:
>>
>>      >>> -12 == -12
>>      True
>>      >>> -12 is -12
>>      False
>>
>> IOW, the literal expression -12 happens to construct a fresh
>> value/object each time CPython parses it.
>
> That's a different matter. However, you appear to be wrong.
>
> print (-12 is -12)
>
> gives True. As does ("abc" is "abc"). I assume constructions for
> immutable values will do the same (([10,20,30] is [10,20,30]) gives
> False because the constructs are mutable, although it's difficult to see
> how in that form).
>
> (This is on 2.7, 3.1 and PyPy. On 3.4.3, (-12 is -12) gives False as you
> say, although (12 is 12) gives True, so not even Python can make up its
> mind how it's supposed to work!)
>
> 3.4.3:
>
> print (-12 is -12)                                     => False
> print (12 is 12)                                       => True
> print (20000000000000000000 is 20000000000000000000)   => True
>
> The others all give True in all cases. It seems that older Python
> versions have a purer object model.
>

No, you don't understand how cPython does things.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence