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On Feb 12, 2015, at 5:43 AM, Steven D'Aprano <steve@pearwood.info> wrote:
On Thu, Feb 12, 2015 at 01:07:52AM -0800, Ian Lee wrote:
Alright, I've tried to gather up all of the feedback and organize it in something approaching the alpha draft of a PEP might look like::
Proposed New Methods on dict ============================
Adds two dicts together, returning a new object with the type of the left hand operand. This would be roughly equivalent to calling:
new_dict = old_dict.copy(); new_dict.update(other_dict)
A very strong -1 on the proposal. We already have a perfectly good way to spell dict += , namely dict.update. As for dict + on its own, we have a way to spell that too: exactly as you write above.
I think this is a feature that is more useful in theory than in practice. Which we already have a way to do a merge in place, and a copy-and-merge seems like it should be useful but I'm struggling to think of any use-cases for it. I've never needed this, and I've never seen anyone ask how to do this on the tutor or python-list mailing lists.
I’ve wanted this several times, explicitly the copying variant of it. I always get slightly annoyed whenever I have to manually spell out the copy and the update. I still think it should use | rather than + though, to match sets. --- Donald Stufft PGP: 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA