On Saturday, January 26, 2019, Steven D'Aprano <[email protected]> wrote: > > > Perhaps you should start by telling us *precisely* what the problem is > that your subclass will solve. Because I don't know what your idea of > dict unpacking is, and how it compares or differs from previous times it > has been proposed.
Dataclasses initialization may be most useful currently implemented syntactic sugar for a dict return value contract that specifies a variable name (and datatype)? Is there a better way to specify a return object interface with type annotations that throws exceptions at runtime that dataclasses? > > Are there any other languages which support dict unpacking? How does it > work there? This about object destructuring in JS is worth a read: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Object_destructuring Here are two simple cases: """ var o = {p: 42, q: true}; var {p: foo, q: bar} = o; console.log(foo); // 42 console.log(bar); // true """ Does it throw an exception when a value is undefined? You can specify defaults: """ var {a: aa = 10, b: bb = 5} = {a: 3}; console.log(aa); // 3 console.log(bb); // 5 """ > > > -- > Steve > _______________________________________________ > Python-ideas mailing list > [email protected] > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ >
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