Discuss when we should end support for Python 3.4

[tleonhardt]

The last release of Python 3.4 was on March 18, 2019. At this point not even security updates will be provided for Python 3.4.

We should discuss at what point we would like to formally stop supporting Python 3.4 At this point there is no burning need to end support for Python 3.4 or anything. However there are a few points in our code that could be cleaned up where we have conditionals that look like the following which could be cleaned up:

# Python 3.4 require contextlib2 for temporarily redirecting stderr and stdout
if sys.version_info < (3, 5):
    # noinspection PyUnresolvedReferences
    from contextlib2 import redirect_stdout
else:
    from contextlib import redirect_stdout

[kmvanbrunt]

Maybe start warning users now like we did for Python 2.7.

[anselor]

It's difficult to warn users by posting here since they likely don't check here. Maybe we can add a check on cmd2 startup and print something on the prompt with a warning about ending support for 3.4?

[kmvanbrunt]

For previous deprecations, we've used the change log to inform users prior to the actual deletion of support.

[anselor]

Right, I think last time we got some people angry because they were only using it as a pip module and not paying attention to the changelog or github project. Printing a message may be a benign way to make it more apparent for those people so they have the opportunity to either update their code or their dependency declarations.

…

On Wed, Apr 10, 2019 at 10:13 AM Kevin Van Brunt ***@***.***> wrote: For previous deprecations, we've used the change log to inform users prior to the actual deletion of support. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#661 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ARIuylX73qlbXzkxMYk8RaM_q-V36bHLks5vffGFgaJpZM4cZR-M> .

[tleonhardt]

If we can find a way to print a warning upon doing a pip install of cmd2, but not every time a cmd2 app runs, then that would be great.

[anselor]

On the flip side, would it be possible for us to publish a final package of cmd2 for Python 3.4 and a different version for 3.5 and greater? Can we put the burden on our side so that breaking changes won't affect users on older versions?

…

On Wed, Apr 10, 2019 at 12:01 PM Todd Leonhardt ***@***.***> wrote: If we can find a way to print a warning upon doing a pip install of cmd2, but not every time a cmd2 app runs, then that would be great. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#661 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ARIuypDSj6ceg-gOaR79LZPyNwbRVut6ks5vfgrsgaJpZM4cZR-M> .

[kmvanbrunt]

Do you mean like we did with cmd2 0.8.9 being the last version meant for Python 2.7?

[anselor]

Right, but it didn't work right last time. It still gave people problems that were still on 2.7.

…

On Wed, Apr 10, 2019 at 12:11 PM Kevin Van Brunt ***@***.***> wrote: Do you mean like we did with cmd2 0.8.9 being the last version meant for Python 2.7? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#661 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ARIuynK5-2BwmojBMMW-q8YfwVgTtA8nks5vfg0ugaJpZM4cZR-M> .

[tleonhardt]

I think other than a brief hiccup, version 0.8.9 of cmd2 still works for Python 2.7.

[tleonhardt]

pip is doing a good job of warning about deprecated Python versions these days. If I try installing anything using pip on a Python 3.4 instance, I get the following warning (warning text prints in yellow):

(py34)$ pip install -U pip
DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one 
supporting it. Please upgrade your Python as Python 3.4 won't be maintained after 
March 2019 (cf PEP 429).

pip's Python 2.7 warning is similar:

(py27)$ pip install -U pip
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please 
upgrade your Python as Python 2.7 won't be maintained after that date. A future version 
of pip will drop support for Python 2.7.

[tleonhardt]

As long as nobody objects, let's plan on remove support in the next release. I'd like it to happen before the 1.0 release because I want the 1.0 release to be clean and there is the potential for us to muck this up and have to do another release.

As long as we do it correctly, people using Python 3.4 will still continue to be able to use the last supported version.

Alternatively if people think it would be better, we can advertise in the next release and then actually remove it in the following one, but still prior to the 1.0 release.