confused about __new__

[Lie Ryan]

On 12/27/2011 04:48 PM, Fredrik Tolf wrote:
> On Mon, 26 Dec 2011, K. Richard Pixley wrote:
>> I don't understand. Can anyone explain?
>
> I'm also a bit confused about __new__. I'd very much appreciate it if
> someone could explain the following aspects of it:
>
> * The manual (<http://docs.python.org/reference/datamodel.html>) says
> that __new__ is "a static method (special-cased so you need not declare
> it as such)". What does "special-cased" mean? Apparently, for
> instance, in OP's case, Python did not automatically detect that it
> should not be bound as a method.

If you declare new in the regular way:

class Foo(object):
     def __new__(cls):
         ...

Python would create __new__ as a static method even without applying the 
staticmethod decorator; that python does not detect to special case 
__new__ when it is added dynamically is probably an oversight in Python 
2.x that was fixed in Python 3.x.