Storing 'unhashable' types in dictionaries by address

[Aahz]

In article <l1u1bjgg3d.fsf at budvar.future-i.net>,
Ed Avis  <ed at membled.com> wrote:
>
>A dictionary requires that its key type be hashable.  This means you
>cannot use lists as keys of a dictionary.  Is there any way round
>this?
>
>I would like to store some 'extra' information associated with some
>lists, but do so outside the lists themselves.  For example this is
>what I would like to write:
>
>l0 = ['strawberry']
>l1 = ['mint', 'choc']
>l2 = ['vanilla', 'liver']
>
># This dictionary stores some extra comments on each flavour.
>d = {}
>d[l0] = 'yum'
>d[l1] = 'so-so'
>d[l2] = 'ugh'

Other people have tried answering your question, but IMO you're simply
using the wrong approach here.  Why not use a class?

    class FlavorList:
        def __init__(self, flavors=None, comment=None):
            if flavors:
                self.flavors = flavors
            else:
                self.flavors = []
            self.comment = comment

    flavor1 = FlavorList(['strawberry'], 'yum')
-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

"In many ways, it's a dull language, borrowing solid old concepts from
many other languages & styles:  boring syntax, unsurprising semantics,
few automatic coercions, etc etc.  But that's one of the things I like
about it."  --Tim Peters on Python, 16 Sep 93