[Python-Dev] Guarantee ordered dict literals in v3.7? (original) (raw)

INADA Naoki songofacandy at gmail.com
Tue Nov 7 19:59:11 EST 2017

On Wed, Nov 8, 2017 at 5:35 AM, Paul G <paul at ganssle.io> wrote:

If dictionary order is not guaranteed in the spec and the dictionary order isn't randomized (which I think everyone agrees is a bit messed up), it would probably be useful if you could enable "random order mode" in CPython, so you can stress-test that your code isn't making any assumptions about dictionary ordering without having to use an implementation where order isn't deterministic.

I could either be something like an environment variable SCRAMBLEDICTORDER or a flag like --scramble-dict-order. That would probably help somewhat with the very real problem of "everyone's going to start counting on this ordered property".

Namespace is ordered by language spec. What does SCRAMBLE_DICT_ORDER in this code?

class A: def init(self): self.a, self.b, self.c = 1, 2, 3

a = A() print(a.dict) a.dict.pop('a') print(a.dict)

Anyway, I'm -1 on adding such option to dict. dict in CPython is complicated already for performance and compatibility reason. I don't want to add more complexity to dict for such reason.

Regards,

INADA Naoki <songofacandy at gmail.com>

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