On Wed, Aug 13, 2014 at 1:50 PM, Ethan Furman <ethan@stoneleaf.us> wrote:
On 08/13/2014 01:19 PM, Guido van Rossum wrote:

On Wed, Aug 13, 2014 at 12:59 PM, Ethan Furman wrote:

-1 on deprecating alternative uses of annotations.

Do you have a favorite alternative annotation use that you actually use (or are likely to)?

My script argument parser [1] uses annotations to figure out how to parse the cli parameters and cast them to appropriate values (copied the idea from one of Michele Simionato's projects... plac [2], I believe).

I could store the info in some other structure besides 'annotations', but it's there and it fits the bill conceptually.  Amusingly, it's a form of type info, but instead of saying what it has to already be, says what it will become.

I couldn't find any docs for scription (the tarball contains just the source code, not even an example), although I did find some for plac. I expect using type annotations to the source of scription.py might actually make it easier to grok what it does. :-)

But really, I'm sure that in Python 3.5, scription and mypy can coexist. If the mypy idea takes off you might eventually be convinced to use a different convention. But you'd get plenty of warning.
 
[1] https://pypi.python.org/pypi/scription  (due for an overhaul now I've used it for awhile ;)
[2] https://pypi.python.org/pypi/plac/0.9.1

--
--Guido van Rossum (python.org/~guido)