[Python-ideas] Trial balloon: adding variable type declarations in support of PEP 484

[Ethan Furman]

On 08/01/2016 02:40 PM, Chris Angelico wrote:
> On Tue, Aug 2, 2016 at 7:31 AM, Guido van Rossum wrote:

>> I'd like to address this in the future, and I think the most elegant
>> syntax would be to let you write these as follows:
>>
>> a: float = 0
>> b: List[int] = []
>> c: Optional[str] = None
>>
>> There are some corner cases to consider.
>
> Additional case, unless it's patently obvious to someone with more 484
> experience than I: what happens with chained assignment?
>
> a = b = c = 0
>
> Does each variable get separately tagged, or does one tag apply to all?

I would think each name would need to be typed:

a: int = b: int = c: int = 0

However, if somebody was doing typing from the get-go I would imagine they would do:

a, b, c: float

--
~Ethan~