[Python-Dev] Type hints -- a mediocre programmer's reaction

[Robert Collins]

On 21 April 2015 at 08:07, Guido van Rossum <guido at python.org> wrote:

> The situation is possibly even bleaker (or happier, depending on your
> position :-) for inline type hints in 3rd party packages -- few package
> authors will be satisfied with supporting only Python 3.5 and later. True,
> you can support Python 3.2 and up by declaring the 3rd party typing package
> as a dependency (unless Python 3.5+ is detected), but I don't expect this to
> become a popular approach overnight.

mypy has a codec for 2.x which strips type annotations -
https://github.com/JukkaL/mypy/tree/master/mypy/codec - while you
can't run mypy under 2.x, you can run it under 3.x to perform the
analysis, and ones code still runs under 2.x.

Another route - the one I've been experimenting with as I get familiar
with mypy - is to just use type comments exclusively. Function type
comments currently break, but that seems like a fairly shallow bug to
me, rather than something that shouldn't work. The advantage of that
route is that editors which make comments appear in subtle colours,
makes the type hints be unobtrusive without specific syntax colouring
support.

-Rob


-- 
Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud