You can in Javascript - but with the caveat that the keys can only be strings. Without that, if Python allowed it, would it do given: a = "xxx" test_dict

You can in Javascript - but with the caveat that the keys can only be strings. Without that, if Python allowed it, would it do given: a = "xxx" test_dict = {a=3, b=2} would it take test_dict to mean {"xxx":3, "b":2} or {"a":3, "b":2} ? JS does the latter always, so the variable a is not related to the literal key a which is understood as an unquoted string "a": > a = "xxx" 'xxx' > test_dict = {a:3, b:2} { a: 3, b: 2 } > test_dict["xxx"] undefined > test_dict["a"] 3