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**Strongly** disagree. I would anticipate using this feature a LOT, and would be excited to see it added. (I would love to replace things like "d2 = d1.copy(); d2.update(d3)" with just "d2 = d1 | d3". In-place "d2 |= d3" is nice in its terseness, but isn't a huge benefit.) But, I completely agree with the arguments in favor of using "|" from the semantic perspective of the operation being much more like a set operation, than a list operation. Further: One angle I don't think I've read from anyone yet (still catching up on the thread tho) is the question of the obscurity of "|" vs the commonality of "+", and how they would likely interact with newcomers. A newcomer is likely going to use "+" a LOT, in all sorts of different situations. Given how non-intuitive dict merging can be, I would rather 'd1 + d2' throw a TypeError than return something unexpected. The more-obscure 'd1 | d2' is likely only going to be used by people who know how the machinery works and go searching for a more concise idiom, and who thus are less likely to be surprised by how it works. -Brian