Tom Anderson wrote:
> On Thu, 18 Jan 2006 [EMAIL PROTECTED] wrote:
>
>> Is there a better way? Thoughts?
>
>
> I was thinking along these lines:
>
> class NamedTuple(tuple):
> def __init__(self, indices, values):
> "indices should be a map from name to index"
> tuple.__init__(self, values)
> self.indices = indices
> def __getattr__(self, name):
> return self[self.indices[name]]
>
> colourNames = {"red": 0, "green": 1, "blue":2}
> plum = NamedTuple(colourNames, (219, 55, 121))
>
> The idea is that it's a tuple, but it has some metadata alongside
> (shared with other similarly-shaped tuples) which allows it to resolve
> names to indices - thus avoiding having two references to everything.
>
> However, if i try that, i get:
>
> Traceback (most recent call last):
> File "<stdin>", line 1, in ?
> TypeError: tuple() takes at most 1 argument (2 given)
>
> As far as i can tell, inheriting from tuple is forcing my constructor to
> only take one argument. Is that the case? If so, anyone got any idea why?
>
This error message is not coming from __init__, but from __new__. See
http://www.python.org/2.2/descrintro.html#__new__
James
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