/usr/bin/python in Python 2 and 3

[Geoffrey Thomas <geofft@ldpreload.com>]

I've written up the proposal I made a few days ago for a /usr/bin/python 
launcher that keeps the API of being Python 2, but lets scripts opt in to 
running on Python 3:

https://ldpreload.com/blog/usr-bin-python-23

I share the desire for /usr/bin/python to maintain its API of being Python 
2, but I also want to be able to write polyglot Python 2/3 scripts that 
run everyhwere -- including on Debian machines with just Python 3. So this 
is a way of "doing something else with /usr/bin/python" that's 
backwards-compatible for us and all the other distros. It even happens to 
be be kind of backwards-compatible for Arch, and Barry's point about 
aligning the desires of the distros is a very good one.

Let me know if you think this is a good or bad idea: I'll submit this as a 
PEP as soon as we have rough consensus that this is a good idea. (We can 
bikeshed the details once the idea itself is a draft PEP.)

--
Geoffrey Thomas
https://ldpreload.com
geofft@ldpreload.com