On Nov 1, 8:13 am, Tim Chase <[EMAIL PROTECTED]> wrote:
> I've got code similar to the following
>
> class Action:
> def __init__(self, ...): pass
> def __call__(self, ...): pass
> def get_help(self, ...): pass
>
> class Backend:
> class _Load(Action):
> def __init__(self, ...): pass # override1
> def __call__(self, ...): pass # override1
> def get_help(self, ...): pass # override1
> load = _Load(...)
> class _Run(Action):
> def __call__(self, ...): pass # override2
> def get_help(self, ...): pass # override2
> run = _Run(...)
>
[snip]
> Is there a more Pythonic way to instantiate sub-classes and
> provide instance-specific implementations without the overhead of
> an unused "anonymous" class cluttering my code/namespace?
Just delete the names after instantiating the class:
del _Load
del _Run
I'm not trying to be snarky, sometimes the straightforward way is the
best.
I like Peter Otten's class decorator solution to this also, and
disagree that such complexity is necessarily unPythonic. If you do it
a lot the complexity could result in an overall simplification. It's
not something you want to casually throw at users, though.
A way to do this in 2.5 and below is to use a class hook (using
__metaclass__ attribute):
def self_instantiate(name,bases,clsdict):
cls = type.__new__(type,name+"_type",
bases,clsdict)
obj = cls()
return obj
class load(Action):
__metaclass__ = self_instantiate
....
Carl Banks
--
http://mail.python.org/mailman/listinfo/python-list
