[Python-ideas] dict.merge(d1, d2, ...) (Counter proposal for PEP 584)

Stefan Behnel stefan_ml at behnel.de
Thu Mar 21 13:53:35 EDT 2019

Steven D'Aprano schrieb am 21.03.19 um 17:21:
> On Thu, Mar 21, 2019 at 09:11:18AM -0700, Guido van Rossum wrote:
>> I don't find it easy to understand or remember that d1.update(d2) modifies
>> d1 in place, while d1.merge(d2) first copies d1.
>> Maybe the name can indicate the copying stronger? Like we did with sorting:
>> l.sort() sorts in-place, while sorted(l) returns a sorted copy.
> How about dict.merged(*args, **kw)? Or dict.updated()?

And then users would accidentally type


and lack the tests to detect that this didn't do anything (except wasting
some time and memory).


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