Re: [Qemu-devel] [PATCH v3 6/8] iotests: Test driver whitelisting in 093

[Kevin Wolf <kwolf@redhat.com>]

Am 17.09.2019 um 15:09 hat John Snow geschrieben:
> On 9/17/19 7:22 AM, Kevin Wolf wrote:
> > Am 17.09.2019 um 13:07 hat Max Reitz geschrieben:
> >> On 17.09.19 10:40, Kevin Wolf wrote:
> >>> Am 17.09.2019 um 10:18 hat Max Reitz geschrieben:
> >>>> On 13.09.19 20:30, John Snow wrote:
> >>>>> I'd still like to define func_wrapper with a nod to the type constraint
> >>>>> it has:
> >>>>>
> >>>>> def func_wrapper(instance: iotests.QMPTestCase, *args, **kwargs):
> >>>>>     [...]
> >>>>>
> >>>>>
> >>>>> Then, you'd write:
> >>>>>
> >>>>> if callable(required_formats):
> >>>>>     fmts = required_formats(instance)
> >>>>> else:
> >>>>>     fmts = required_formats
> >>>>
> >>>> Yep, that anyway.  (Although I didn’t know about the “param: type”
> >>>> syntax and put that constraint in a comment instead.  Thanks again :-))
> >>>
> >>> Note that function annotations are Python 3 only, so we can't use that
> >>> syntax yet anyway. If you want to use type hints that are understood by
> >>> tools (like mypy) and compatible with Python 2, you have to use
> >>> something like this (feel free to be more specific than Any):
> >>
> >> Do we really feel like staying compatible with Python 2, though?
> > 
> > Feel like it? No.
> > 
> > It's more that we are compelled to do so because we only deprecated it
> > in 4.1.
> 
> Sorry for the impromptu lesson on type hints in 3.5! I added that in to
> my suggestion as a demonstrative example and didn't mean for you to use
> it as-is, sorry for not making that clear.
> 
> I'm confused about the Python3 deprecation timeline. Normally we'd
> follow our standard approach, but it does hit EOL at the end of this
> year, so do we drop support then, too? I have the memory of a goldfish I
> suppose, and can't quite remember our conclusions, if any, of previous
> discussions on this subject.

It shouldn't make a difference actually because deprecation in 4.1 means
that 4.2 (in December) will be the last release that must still support
Python 2, and we can switch to Python 3 for 5.0.

> If we do drop python2 though, the new minimum version appears to be 3.5
> because that's what ships in EPEL. That'd give us standardized type
> hints that we can use for static analysis tools.

Actually I seem to remember I suggested that we should make 3.5 the
minimum Python 3 version, and I thought a patch to this effect had been
merged, but now I can't find any such check in configure. Maybe I should
find the old thread again to see if there was any reason not to do this.

Personally, I would have preferred 3.6 because it brings in variable
annotations, but I think last time the conclusion was that it would be
3.5 indeed.

Kevin