On 2007-04-23, Steve Holden <[EMAIL PROTECTED]> wrote: > Neil Cerutti wrote: >> So the question becomes: Why do Python dictionaries require >> keys to be of an immutable type? > > Because otherwise people would expect to be able to use a list > to select a dictionary entry even after they'd modified > elements of the list after creating the dictionary entry. Which > they couldn't. So Python doesn't let them use lists.
The interpreter explains it: "A list is not a hashable object." Choosing a hash table instead of some kind of balanced tree seems to be just an optimization. ;) -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
