PEP 584 – Add + and – operators to the built-in dict class

Re:PEP 584 – Add + and – operators to the built-in dict class by rbanffy on Wednesday March 06, 2019 @06:50AM (#19318194)

Why not raise a ValueError and let the programmer figure out what The Right Thing To Do is when you add two dicts that have the same key with a different value?

I assume the same key with the same value would be OK, but I'm not really sure it's a good idea for it to be OK.

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Re:PEP 584 – Add + and – operators to the built-in dict class by zimablue on Wednesday March 06, 2019 @08:15AM (#19318614)

You can't do value comparison without making dict item comparison a pissed in function or making dict values immutable. If you're doing something that really looks like a mathematical Union that will raise if there's any overlap then it's a really confusing abuse of notation. I don't think there's a way out.

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