__getitem__ method on (meta)classes

[Leif K-Brooks]

ron at flownet.com wrote:
> Why doesn't this work?
> 
> 
>>>>def foo(lst):
> 
> ...   class baz(object):
> ...     def __getitem__(cls, idx): return cls.lst[idx]
> ...     __getitem__=classmethod(__getitem__)
> ...   baz.lst = lst
> ...   return baz
> ...
> 
> I thought x[y] and x.__getitem__(y) were supposed to always be
> synonymous.

No, with new-style classes, x[y] and type(x).__getitem__(y) are 
synonymous. This works:

 >>> def foo(lst):
...  class bar(type):
...   def __getitem__(self, index):
...    return self.lst[index]
...  class baz(object):
...   __metaclass__ = bar
...  baz.lst = lst
...  return baz
...
 >>> foo([1,2,3])[0]
1