It's not just because of the set syntax; it's also because Python dicts don't treat their keys as symbols, but rather evaluate them as expressions, whereas JS e

It's not just because of the set syntax; it's also because Python dicts don't treat their keys as symbols, but rather evaluate them as expressions, whereas JS evaluates keys as symbols by default and requires `{[key]: val}` to evaluate them. So in Python you'd have to do something funky where `{a: a}` is `{value_of_a: value_of_a}`, but, say, `{a:}` is `{"a": value_of_a}`.