On Nov 2, 2016, at 12:49 PM, Nick Coghlan
wrote: hmm -- I don't think that's the code-writers job -- it's the deployers job. Other than choosing which python *version* I want to use, I can happily develop with system python and pip, and then deploy with conda -- or vice versa. INdeed, I can develop on Windows and deploy on LInux, or....
You still need to decide which versions you're going to test against, and which bug reports you're going to accept as potentially valid feedback (e.g. very few people running upstream community projects will accept "doesn't run on Python 2.5" as a valid bug report any more, and RHEL/CentOS 7, Software Collections, and conda have been around for long enough now that most won't accept "doesn't run on 2.6" either)
though if you meant pypy vs iron python vs cPython when you meant "runtime" then yes, with the dependency issue, you really do need to make that choice upfront.
I also mean 2.6 vs 2.7 vs 3.4 vs 3.5 vs 3.6, etc
There are still platform differences too, we regularly get bugs that only are exposed on Anaconda or on Ubuntu’s Python or on RHEL's Python or on Python.org’s OS X installers etc etc. Basically every variation has a chance to introduce a bug of some kind, and if you’re around long enough and you’re used enough you’ll run into them on every system. As someone writing that code you have to decide where you draw the line for what you support or not (for instance, you may support Ubuntu/RHEL/Anaconda, but you may decide that any version of CPython running on HPUX is not supported). — Donald Stufft