[Python-Dev] Please reject or postpone PEP 526

[Chris Angelico]

On Tue, Sep 6, 2016 at 2:17 AM, Steven D'Aprano <steve at pearwood.info> wrote:
>> > The type comment systax is required for Python 2 and backwards-
>> > compatibility. That's a given.
>>
>> Sure, but all type checkers will not have to care about Python 2.
>
> They will have to care about type comments until such time as they are
> ready to abandon all versions of Python older than 3.6.

More specifically, until *the code they check* can abandon all <3.6.
If the checker itself depends on new features (say, an improved AST
parser that retains inline comments for subsequent evaluation), you
could say "You must have Python 3.6 or better to use this checker",
but the application itself would still be able to run on older
versions. That's another reason not to delay this PEP until 3.7, as
it'd push _everything_ another 18 months (or more) into the future.

ChrisA