Switch Simfactory to use Python3

[Steven R. Brandt]

Python2 is officially deprecated. Is it time to move to Python3? See the py3 branch.

[Roland Haas]

Decided against this switch before the release.

[Roland Haas]

This is becoming a bit more urgent since both Debian and Ubuntu seem to be retiring /usr/bin/python and python2 packages are no longer being updated.

[Steven R. Brandt]

Do we want to postpone this for 2021?

[Roland Haas]

Would be best if we can figure out what Debian / Ubuntu’s plans are. /usr/bin/python2 is still fine, just /usr/bin/python is no good anymore. If possible we should try and avoid the situation we had with gcc/gfortran-10 where things broke just after the release.

Otherwise, yes delaying might well be feasible though we may have to comb our python scripts eg GW150914.rpar for #!/usr/bin/env python or similar in the hashbang line.

[Roland Haas]

Pull request is here: https://bitbucket.org/simfactory/simfactory2/pull-requests/47

[William Gabella]

I agreed to pull and review, test as well as I can. Some kind of test suite would be nice.

See Steve’s other pull request on the Python2 version with the --test switch on “sim” which will be changed to --dryrun . Might be a nice way to test sim over a broad range of options. See tickets #2482 and #2483.

Zach shared a Python3 “lint” er at https://lgtm.com/projects/b/simfactory/simfactory2/?mode=list

which as of now shows 4 errors, 27 warnings, 161 recommendations. Overall code quality “D” Unclear to me whether this is the Steve Python3 code or the current Python2 code.

Also our current Simfactory is officially Simfactory2; that does not mean Python2. There is a moribund project Simfactory3 out there.

[Roland Haas]

Applied as git hash 7ce80711 "simfactory: add "coding: ascii" marker to all source files" of simfactory2