I understand auto-generating the __hash__ (and __eq__) for a frozen container; that is just convenient.
But why is there any desire to autogenerate a __hash__ for something that isn't frozen? Like a list or dict, the normal case would be for it not to have a hash at all, and the author *should* write out any explicit exceptions. The objection to that seems to be that someone might forget to add another field to the hash during later maintenance -- but so what? __hash__ should reference a subset of the fields used for equality, and strict subsets are OK. It *should* ignore some fields if that will provide the right balance between quick calculation and sufficient dispersion. If the record is complicated enough that forgetting a field is a likely problem, then the hash is probably already sufficiently complex without those new fields. -jJ _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
