On Tue, Feb 15, 2011 at 12:29 PM, Jeremy <jlcon...@gmail.com> wrote:
> I have a container object. It is quite frequent that I want to call a
> function on each item in the container. I would like to do this whenever I
> call a function on the container that doesn't exist, i.e., the container
> would return an attribute error.
s/function/method/
> For example
>
> class Cont(object):
> def __init__(self):
> self.items = []
>
> def contMethod(self, args):
> print("I'm in contMethod.")
>
> def __getattr__(self, name):
> for I in self.items:
> # How can I pass arguments to I.__dict__[name]?
> I.__dict__[name]
>
<snip>
> The trouble I'm getting into is that I can't pass arguments to the attributes
> in the contained item. In the example above, I can't pass 'abc' to the
> 'itemMethod' method of each item in the container.
>
> Does someone know how I can accomplish this?
Recall that:
x.y(z)
is basically equivalent to:
_a = x.y
_a(z)
So the arguments haven't yet been passed when __getattr__() is
invoked. Instead, you must return a function from __getattr__(); this
function will then get called with the arguments. Thus (untested):
def __getattr__(self, name):
def _multiplexed(*args, **kwargs):
return [getattr(item, name)(*args, **kwargs) for item in self.items]
return _multiplexed
Cheers,
Chris
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