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[Alex Martelli]

Greg Ewing <greg at cosc.canterbury.ac.nz> wrote:

> Alex Martelli wrote:
> > Since an immediate instance of type object has no possible use except as
> > a unique, distinguishable placeholder,
> 
> That's not true -- you can also assign attributes to such
> an object and use it as a record. (It's not a common use,
> but it's a *possible* use!)

That's not true -- you cannot do what you state (in either Python 2.3 or
2.4, it seems to me).  Vide:

protagonist:~ alex$ python2.3
Python 2.3 (#1, Sep 13 2003, 00:49:11) 
[GCC 3.3 20030304 (Apple Computer, Inc. build 1495)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> x23=object()
>>> x23.foo=23
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
AttributeError: 'object' object has no attribute 'foo'
>>>
 
protagonist:~ alex$ python2.4
Python 2.4a3 (#1, Sep  3 2004, 22:25:02) 
[GCC 3.3 20030304 (Apple Computer, Inc. build 1640)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> x24=object()
>>> x24.bar=24
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
AttributeError: 'object' object has no attribute 'bar'
>>> 


If an object() could be used as a Bunch I do think it would be
reasonably common.  But it can't, so I insist that its role as
sentinel/placeholder is the only possibility.


Alex