Another try at Python's selfishness

[Jean-Paul Calderone]

On Fri, 3 Feb 2006 15:27:51 -0500, Terry Reedy <tjreedy at udel.edu> wrote:
>
>"Magnus Lycka" <lycka at carmen.se> wrote in message
>news:drvd56$nb3$1 at wake.carmen.se...
>> n.estner at gmx.de wrote:
>> Today, Python has a syntactic shortcut. If 'a' is an
>> instance of class 'A', a.f(x,y,z) is a shortcut for
>> A.f(a,x,y,z). If you don't use the shortcut, there is
>> no magic at all, just the unusual occurence of a type
>> check in Python!
>
>As was once pointed out to me some years ago, when I wrote something
>similar, a.f() is not just a shortcut for A.f(a) [a.__class__.f(a)].   The
>latter only looks for f in the class A namespace while the former also
>looks in superclass namespaces.  The 'magical' part of accessing functions
>via instances is the implementation of dynamic inheritance.

I'm not sure I follow.  Surely you're not suggesting that this doesn't work:

    >>> class X:
    ...     def foo(self):
    ...         print 'X.foo', self
    ... 
    >>> class A(X):
    ...     pass
    ... 
    >>> o = A()
    >>> A.foo(o)
    X.foo <__main__.A instance at 0xb7cab64c>
    >>> 

But I can't think what else you might mean.

>
>Terry Jan Reedy
>
>
>
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