[Doc-SIG] Does the "is" operator only matter for mutable object?

[Steven D'Aprano]

INADA Naoki wrote:
> In
> http://docs.python.org/py3k/tutorial/datastructures.html#comparing-sequences-and-other-types
> ,
> 
> The operators is and is notcompare whether two objects are really the same
>> object;
>> this only matters for mutable objects like lists.
> 
> 
> I think this notation may confuse readers of the tutorial. For example, pep8
> recommands
> using is operator for immutable singleton objects like None.
> 
> Shall we remove letter part?

Rather than completely remove it, I would reword it:

The operators is and is not compare whether two objects are really the 
same object; this usually only matters for mutable objects like lists, 
or for testing against singletons like None.



-- 
Steven