Hi Jim,
On 18 April 2014 23:46, Jim J. Jewett <jimjjew...@gmail.com> wrote:
> (2) Is "the item will be hashed at least once" a language guarantee?
I think that a reasonable implementation needs to hash at least once
all keys that are added to the dictionary. Otherwise we end up, as
you said, with a dictionary that contains non-hashable keys: this
crashes when it grows and tries to convert from a list storage to a
hash table. This is against the expectations and probably against the
language spec...
It's a bit unclear to me if the language spec requires "if [ ] in
mydict:" to raise TypeError, as the key doesn't get added to the dict
in this case. Similarly for "[ ] in { }" where the dictionary is
empty anyway. I would say yes, erring on the side of caution...
A bientôt,
Armin.
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