[issue27253] More efficient deepcopying of Mapping

Changes by Serhiy Storchaka : -- resolution: -> rejected stage: patch review -> resolved status: open -> closed ___ Python tracker

[issue27253] More efficient deepcopying of Mapping

Raymond Hettinger added the comment: Is this ever needed? I'm not sure whether all these patches are being driven by reasonable use cases or whether it is just something that could be done. I thought the whole point of the views was to avoid copying. If so, there is a design principle that

[issue27253] More efficient deepcopying of Mapping

New submission from Serhiy Storchaka: Mapping views supports copying and deepcopying by default (using pickle protocol). But copy.deepcopy() is not efficient for KeysView and ValuesView. It copies all keys and values, while KeysView needs copying only keys and ValuesView needs copying only