[Python-Dev] Guarantee ordered dict literals in v3.7?

[INADA Naoki]

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 SCRAMBLE_DICT_ORDER 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>