On Fri, 17 Jul 2020 13:42:09 +0100 Bruce Richardson <bruce.richard...@intel.com> wrote:
> On Thu, Jul 16, 2020 at 02:01:21PM -0700, Stephen Hemminger wrote: > > On Thu, 16 Jul 2020 16:44:29 +0200 > > Robin Jarry <robin.ja...@6wind.com> wrote: > > > > > 2020-07-13, Bruce Richardson: > > > > In the absense of a "proper" solution, is the simplest option to > > > > change the shebangs to all be python3, but leave the python2 > > > > compatibility in place, and add the warnings for anyone running it > > > > explicitly using python2? > > > > > > I have found a hacky[1] but somewhat not too ugly way to dynamically use > > > any available python interpreter. > > > > > > Basically, the scripts shebangs become: > > > > > > #!/bin/sh > > > # shell script hack to dynamically use any available python interpreter > > > ''':' > > > if command -pv python3 >/dev/null 2>&1; then > > > exec python3 "$0" "$@" > > > else > > > exec python2 "$0" "$@" > > > fi > > > ''' > > > # real python code starts here > > > > > > This hack obviously would remain only for the time where we still have > > > python 2 support and can be removed after 20.08 is released. > > > > > > What do you think? > > > > > > [1] https://unix.stackexchange.com/a/66242 > > > > > > > No. > > I could live with this, but I think that python3 is widespread enough now > to just go with the simpler solution of python3 by default while still > allowing others to run with python2 explicitly if they so desire. > > I think we have covered a number of options, but I'm not sure we have > converged on an agreed solution. Here are the options I would consider: > > 0. Do nothing to the code, and just print deprecation notice in docs. This > will violate the previously documented plan, but won't break anything for > anyone. > 1. Just add deprecation notice but leave shebang lines unchanged, meaning > lots of people see the notice but don't need to care since they just call > the script. > 2. As #1, but check if python3 is available and only print deprecation > notice if not > 3. Add deprecation notice, and change shebang lines to use python3. This > means that anyone who does not have python3 installed will see a breaking > change > 4. Change shebangs to use python3 and detect at "make" build time if > python3 is available. If py3 is unavailable, adjust shebang and add > deprecation warning on "make install". > 5. Use shell-hack above. > > Any other options I'm missing? > > For me, I think I can live with all options bar #1. Probably my top > preference would be #4 or #2, with #0 and #4 next best thereafter. > 6. Change shebangs to use python3 and don't bother detecting. Since distributions will have python3. 7. Change shebangs and keep the python2 compat imports 8. Other alternative I have seen in code is to use try block in the import section: try: # for Python2 from Tkinter import * except ImportError: # for Python3 from tkinter import * But supporting python2 for a longer time makes no sense. I would go for #0 for 20.08 and full python3 in 20.11 (#3)
