Open Stack

On Sat, 2019-01-26 at 13:29 -0500, Doug Hellmann wrote:
> I agree with your concerns about code churn. I think it’s still useful to run a small experiment to demonstrate how we
> might actually benefit from them though, which applying them to one library would let us do. 
> 
> On Jan 26, 2019, at 1:18 PM, Morgan Fainberg <morgan.fainberg at gmail.com> wrote:
> 
> > Honestly, I would wait for this for the U release. We can then go to the annotation style and if needed update
> > docstrings at the same time. My concern with pushing this now is a high churn of code that should be duplicated once
> > we drop PY2 support.
> > 
> > Other than my above concerns the type checking in mypy would be great to have. 
> > 
> > --Morgan
> > 
> > On Sat, Jan 26, 2019, 09:14 Sergey Vilgelm <sergey at vilgelm.info wrote:
> > > Cyril,
> > > 
> > > We have lots of doc strings in rst format and many of them already have the `@param` and `@type` tags. Does the
> > > mypy support this format or we should to rewrite doc string and add the `type:` tags just for mypy?
> > > 
> > > --
> > > Sergey Vilgelm
> > > https://www.vilgelm.info
> > > On Jan 26, 2019, 9:07 AM -0600, Cyril Roelandt <cyril at redhat.com>, wrote:
> > > > Hello Doug,
> > > > 
> > > > On 01/26/19 09:02, Doug Hellmann wrote:
> > > > > We're still required to support python 2 through the beginning of the U
> > > > > cycle [5]. Is it possible to apply the type hints in a way that allows
> > > > > us to maintain that support?
> > > > > 
> > > > > [5] https://governance.openstack.org/tc/resolutions/20180529-python2-deprecation-timeline.html
> > > >  
> > > > There are two ways to apply type hints:
> > > > 1) Use a new syntax that only works with Python 3
> > > > 2) Use comments (see my github branch, where comments starting with
> > > > "type:" can be found)
there is also a third, looping stephen into the conversation.
stephen did some experiments in this regard in the past.
the commet form is backwards compatiabl but you can also put thetype hints in 
a seperate .pyi file. The .pyi file version has the advantage of also working for c modules
and not modifying any of the existing code.

we previously disscused the idea of using 
https://github.com/Instagram/MonkeyType
to auto discover the types of existing libs and generate the stub .pyi files.
ideally we should just be able to run our existing unit/functional test under mockeytype 
to discover the relevent types and create the pyi files.

i dont think stephen or i had the chance to persue that since we discuseed it in denver.


> > > > 
> > > > I used the second approach in order to not break Python 2 compatibility.
> > > > 
> > > > 
> > > > Regards,
> > > > Cyril
> > > >