[Python-Dev] Type hints -- a mediocre programmer's reaction (original) (raw)

Harry Percival harry.percival at gmail.com
Mon Apr 20 22:50:05 CEST 2015

stub files are only used to type-check users of a module. If you want a module itself to be type-checked you have to use inline type hints

is this a fundamental limitation, or just the current state of tooling?

On 20 April 2015 at 21:48, Harry Percival <harry.percival at gmail.com> wrote:

> "I hate stub files. [...] in my opinion, [it] just about guarantees a maintenance burden that will fall by the side of the road.

I'm not so pessimistic. It's not like documentation or docstrings or comments -- the whole point is that it should be very easy to have an automated check for whether your stubs are in sync with your source, because both are in code. Unlike docs or comments which can easily become out of date, because there's no automated process to tell you they need updating... I'm thinking of it as a thing your editor will warn you of. Like pyflakes warnings about unused variables & co, I'm never happy until I've silenced them all in a file, and similarly, your editor will keep bugging you until you've got your stubs inline with your code...

On 20 April 2015 at 20:37, Isaac Morland <ijmorlan at uwaterloo.ca> wrote: On Mon, 20 Apr 2015, Paul Moore wrote:

On 20 April 2015 at 19:41, Barry Warsaw <barry at python.org> wrote:

tldr; type hints in python source are scary. Would reserving them for stub files be better?

I think so. I think PEP 8 should require stub files for stdlib modules and strongly encourage them for 3rd party code. Agreed. I have many of the same concerns as Harry, but I wouldn't have expressed them quite as well. I'm not too worried about actually removing annotations from the core language, but I agree that we should create a strong culture of "type hints go in stub files" to keep source files readable and clean. On that note, I'm not sure "stub" files is a particularly good name. Maybe "type files" would be better? Something that emphasises that they are the correct place to put type hints, not a workaround. How about "header" files? (ducks...) Isaac Morland CSCF Web Guru DC 2619, x36650 WWW Software Specialist

Python-Dev mailing list Python-Dev at python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/hjwp2%40cantab.net

-- ------------------------------ Harry J.W. Percival ------------------------------ Twitter: @hjwp Mobile: +44 (0) 78877 02511 Skype: harry.percival

--

Harry J.W. Percival

Twitter: @hjwp Mobile: +44 (0) 78877 02511 Skype: harry.percival -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20150420/be33160f/attachment.html>

More information about the Python-Dev mailing list