[Python-ideas] An identity dict

[Benjamin Peterson]

Lie Ryan <lie.1296 at ...> writes:
> it may be useful, but if you can emulate it relatively easily with
> regular dict, why bother with a new type?

Why defaultdict then? It can be implemented just fine with dict.setdefault.
identitydict avoids the unnatural method of having the key and value as value of
the dictionary, resulting in contortions everytime the dictionary is manipulated.