I think some people in favor of PEP 584 just want single expression for merging dicts without in-place update.
But I feel it's abuse of operator overload. I think functions and methods are better than operator unless the operator has good math metaphor, or very frequently used as concatenate strings. This is why function and methods are better: * Easy to search. * Name can describe it's behavior better than abused operator. * Simpler lookup behavior. (e.g. subclass and __iadd__) Then, I propose `dict.merge` method. It is outer-place version of `dict.update`, but accepts multiple dicts. (dict.update() can be updated to accept multiple dicts, but it's not out of scope). * d = d1.merge(d2) # d = d1.copy(); d.update(d2) * d = d1.merge(d2, d3) # d = d1.copy(); d.update(d2); d2.update(d3) * d = d1.merge(iter_of_pairs) * d = d1.merge(key=value) ## Merits of dict.merge() over operator + * Easy to Google (e.g. "python dict merge"). * Easy to help(dict.merge). (or dict.merge? in IPython) * No inefficiency of d1+d2+d3+...+dN, or sum(list_of_many_dicts) * Type of returned value is always same to d1.copy(). No issubclass, no __iadd__. ## Why not dict.updated()? sorted() is a function so it looks different from L.sort() But d.updated() is very similar to d.update() for human eyes. ## How about d1 - d2? If it is really useful, it can be implemented as method too. dict.discard(sequence_of_keys) Regards, -- INADA Naoki <songofaca...@gmail.com> _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
