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On Fri, 18 Oct 2019 at 14:33, Richard Musil <risa2000x@gmail.com> wrote:
I have no problem with any example you mentioned above, yet I consider proposed meaning for '+' symbol in this PEP context fundamentally different from either "arithmetic" or "concatenation" meaning, used in the previous examples, because it does not only adds, but also changes the values. Technically we can call set union also an "add" operation, yet we use different semantics to express it, for exactly the same reason, it is not "arithmetic" nor, "concatenation", but something different.
IMO, debating the "meaning" of addition, and whether the + operator is appropriate here, is not the key question. The real questions for me are whether the update operation is used frequently enough to require an additional way of spelling it, and whether using the + operator leads to cleaner more readable code. I've personally almost never needed the dictionary update operator, so for me, having a second way of spelling it is probably not going to be of any real benefit (and may be a net disadvantage, because I'll have to understand both forms in code I support). I don't really have a view on whether the operator or the method would result in cleaner code, but I'd expect that given how rarely I use the operation, a named method would be easier to follow (for me). All of the above is just my subjective opinion. Objective information is likely to only be available by someone looking at a body of real world code and demonstrating what difference the proposed operator would make to it (maybe someone did that already - I've not been following this thread closely). Paul