[Python-ideas] Dict joining using + and +=

Anders Hovmöller boxed at killingar.net
Tue Mar 5 02:05:25 EST 2019

> Adding the + operator for dictionaries feels like it would be a mistake in that it offers at most sugar-y benefits, but introduces the significant drawback of making it easier to introduced unintended errors. 

I disagree. This argument only really applies to the case "a = a + b", not "a = b + c". Making it easier and more natural to produce code that doesn't mutate in place is something that should reduce errors, not make them more common.

The big mistake here was * for strings which is unusual, would be just as well served by a method, and will ensure that type errors blow up much later than it could have been. This type of mistake for dicts when you expected numbers is a much stronger argument against this proposal in my opinion. Let's not create another pitfall! The current syntax is a bit unwieldy but is really fine. 

/ Anders 

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