list vs tuple

[Aahz Maruch]

In article <buqw6.1999$sk3.675030 at newsb.telia.net>,
Fredrik Lundh <fredrik at effbot.org> wrote:
>Mark Pilgrim wrote
>>
>> It was my understanding that only tuples containing immutable objects
>> could be used as dictionary keys.  For instance, (1,2,3) can be, and
>> ("a","b","c") can be, but ([1,2,3], ["a","b","c"]) can not, because
>> the underlying objects could mutate and cause problems.  (Wow, that
>> sounds like a bad sci-fi movie.)  Is this true?
>
>no python interpreter within reach today?
>
>>>> d = {}
>>>> d[(1, 2, 3)] = 1
>>>> d[("a", "b", "c")] = 2
>>>> d[([1, 2, 3], ["a", "b", "c"])] = 3
>Traceback (most recent call last):
>  File "<stdin>", line 1, in ?
>TypeError: unhashable type

Sure, but someone could create a class with __hash__ and do some weird
stuff that way.  Not Recommended.
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