One of the open questions with the Python 3 migration is the eventual fate of /usr/bin/python.
In response to a question from Robert Kuska, Barry Warsaw recently pointed me towards Geoffrey Thomas's design proposal for Debian: https://ldpreload.com/blog/usr-bin-python-23 The gist of the idea is to make /usr/bin/python a custom launcher rather than a symlink to a specific Python interpreter, and then have a simple "magic comment" syntax to specify version compatibility. (These would only apply for a "python" shebang line - "python2" and "python3" would still be symlinks to a specific interpreter) Python 2 only (fail if Python 2 not installed): No comment # pyversion: 2.x+ Python 3 only (fail if Python 3 not installed): # pyversion: 3.x+ Python 2 & 3 compatible: # pyversion: 2.x+, 3.x+ In all cases, the ".x" would be a *specific* Python version. Thomas has a very simple proof of concept implementation at https://github.com/geofft/pythonmux/blob/master/pythonmux.c that just uses "/usr/bin/pythonX.Y" as its registration mechanism for making the launcher aware of additional runtimes. It seems to me that this would be an excellent starting point for preserving "/usr/bin/python" compatibility for end user scripts. Providing such a runtime multiplexer would also potentially provide a way to introduce per-user configuration of the "default Python", such that a user could run their *own* scripts in a different Python interpreter by default (e.g. an SCL, or PyPy), without having to touch the default Python at the system level (i.e. when running Python scripts as root). Regards, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ python-devel mailing list python-devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/python-devel
