Re: [Jython-users] jython bug?: >>> [].count(None) is 0

[Samuele P. <ped...@bl...>]

From: "Updike, Clark" <Cla...@jh...>
> I didn't find anything on this in the bug database so here goes:
> 
> Jython 2.1 on java1.3.1_01 (JIT: null)
> Type "copyright", "credits" or "license" for more information.
> >>> [].count(None) is 0
> 0 
> >>> [].count(None) == 0
> 1
> >>>
> 
> And just to make sure I wasn't 
> misunderstanding something about python:
> 
> Python 2.1.1 (#20, Jul 20 2001, 01:19:29) [MSC 32 bit (Intel)] on win32
> Type "copyright", "credits" or "license" for more information.
> >>> [].count(None) is 0
> 1
> >>> [].count(None) == 0
> 1
> >>>
> 
> 
> These seems suprisingly fundamental that it hasn't come up already.  
> Is it a bug?
> 

there are no guarantees about number identities:

Python 2.2.1 (#34, Apr  9 2002, 19:34:33) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> a=99
>>> a is 99
1
>>> a=100
>>> a is 100
0
>>>

regards.