When are immutable tuples *essential*? Why can't you just use lists *everywhere* instead?

[Chris Cioffi]

On 23 Apr 2007 17:19:15 +0200, Neil Cerutti <horpner at yahoo.com> wrote:
> So the question becomes: Why do Python dictionaries require keys
> to be of an immutable type?

Dictionary keys are hashed values.  If you change the key, you change
the hash and lose the pointer to the referenced object.

Or:  Because.  ;-)

Chris
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