On: NumPy 1.16 is the last release to support Python 2...

[acqq]

You should assume that python means “2” and python3 what it says in the name. The bigger problem is that invoking “python3” and having a script developed for “python3” still doesn’t guarantee that the script will work, there were incompatible changes during python3 history.

[joshuamorton → acqq]

This has always been true. New syntax or libraries were added in almost every major Python version.

If python2 was python2.2, it wouldn't support `with`. It's just that python2 has been Python 2.7 for a decade, so it's been relatively stable.

[ThatPlayer → acqq]

Arch Linux has the packages the other way around: the 'python' package is Python 3 while there is a python2 package and binary.

I guess Ubuntu has it that way to stop the breaking changes however

[detaro → ThatPlayer]

You should expect python to be Python 2 because that's the official recommendation, for compatibility: https://www.python.org/dev/peps/pep-0394/

New code has no problem explicitly requesting python3, old code needs changing to request Python 2, but if you touch it anyways it's of course safer to make that change.

[Macha → detaro]

In case anyone thinks Arch is being crazy here and ignored the PEP (and doesn't read the PEP), note the change here was written in 2011 and approved in 2012 based on Arch's experience moving to python 3 by default in 2010.

[VWWHFSfQ → acqq]

there were incompatible changes during python2 history as well. RHEL shipped Python 2.4 forever, and now ships 2.7. There are many breaking changes between those two versions.

[slondr → acqq]

#!/usr/bin/env python3