<div dir="ltr"><br><br><div class="gmail_quote"><div dir="ltr">On Tue, Oct 16, 2018 at 10:58 AM Zane Bitter <<a href="mailto:zbitter@redhat.com">zbitter@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 15/10/18 8:00 PM, Monty Taylor wrote:<br>
> On 10/15/2018 06:39 PM, Zane Bitter wrote:<br>
>><br>
>> In fact, as far as we know the version we have to support in CentOS <br>
>> may actually be 3.5, which seems like a good reason to keep it working <br>
>> for long enough that we can find out for sure one way or the other.<br>
> <br>
> I certainly hope this is not what ends up happening, but seeing as how I <br>
> actually do not know - I agree, I cannot discount the possibility that <br>
> such a thing would happen.<br>
<br>
I'm right there with ya.<br>
<br>
> That said - until such a time as we get to actually drop python2, I <br>
> don't see it as an actual issue. The reason being - if we test with 2.7 <br>
> and 3.7 - the things in 3.6 that would break 3.5 get gated by the <br>
> existence of 2.7 for our codebase.<br>
> <br>
> Case in point- the instant 3.6 is our min, I'm going to start replacing <br>
> every instance of:<br>
> <br>
> "foo {bar}".format(bar=bar)<br>
> <br>
> in any code I spend time in with:<br>
> <br>
> f"foo {bar}"<br>
> <br>
> It TOTALLY won't parse on 3.5 ... but it also won't parse on 2.7.<br>
> <br>
> If we decide as a community to shift our testing of python3 to be 3.6 - <br>
> or even 3.7 - as long as we still are testing 2.7, I'd argue we're <br>
> adequately covered for 3.5.<br>
<br>
Yeah, that is a good point. There are only a couple of edge-case <br>
scenarios where that might not prove to be the case. One is where we <br>
install a different (or a different version of a) 3rd-party library on <br>
py2 vs. py3. The other would be where you have some code like:<br>
<br>
if six.PY3:<br>
some_std_lib_function_added_in_3_6()<br>
else:<br>
py2_code()<br>
<br>
It may well be that we can say this is niche enough that we don't care.<br>
<br>
In theory the same thing could happen between versions of python3 (e.g. <br>
if we only tested on 3.5 & 3.7, and not 3.6). There certainly exist <br>
places where we check the minor version.* However, that's so much less <br>
likely again that it definitely seems negligible.<br>
<br>
* e.g. <br>
<a href="https://git.openstack.org/cgit/openstack/oslo.service/tree/oslo_service/service.py#n207" rel="noreferrer" target="_blank">https://git.openstack.org/cgit/openstack/oslo.service/tree/oslo_service/service.py#n207</a><br>
<br>
> The day we decide we can drop 2.7 - if we've been testing 3.7 for <br>
> python3 and it turns out RHEL/CentOS 8 ship with python 3.5, then <br>
> instead of just deleting all of the openstack-tox-py27 jobs, we'd <br>
> probably just need to replace them with openstack-tox-py35 jobs, as that <br>
> would be our new low-water mark.<br>
> <br>
> Now, maybe we'll get lucky and RHEL/CentOS 8 will be a future-looking <br>
> release and will ship with python 3.7 AND so will the corresponding <br>
> Ubuntu LTS - and we'll get to only care about one release of python for <br>
> a minute. :)<br>
> <br>
> Come on - I can dream, right?<br>
<br>
Sure, but let's not get complacent - 3.8 is right around the corner :)<br>
<br></blockquote><div><br></div><div>Btw I confirmed this morning that the plan for 20.04 LTS is to have 3.8, so it really is around the corner.<br></div><div><br></div><div>Thanks,</div><div>Corey<br></div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
cheers,<br>
Zane.<br>
<br>
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