python32 @3.2.3 doesn't create a python3 link while python2 is installed

[macports.jgonggrijp@…]

I have python26, python27 and python32 installed on Mac OS X 10.6.8 with Xcode 3.2.6. Normally when Python 2 and Python 3 are installed alongside on a unixy system there should be both a python2 link and a python3 link, as detailed in PEP 394: ​http://www.python.org/dev/peps/pep-0394/

MacPorts does indeed install a python2 command, but no python3 command. This is what I get when I run ls /opt/local/bin/python*:

/opt/local/bin/python		/opt/local/bin/python2.6-config	/opt/local/bin/pythonw
/opt/local/bin/python-config	/opt/local/bin/python2.7	/opt/local/bin/pythonw2
/opt/local/bin/python2		/opt/local/bin/python2.7-config	/opt/local/bin/pythonw2.6
/opt/local/bin/python2-config	/opt/local/bin/python3.2	/opt/local/bin/pythonw2.7
/opt/local/bin/python2.6	/opt/local/bin/python3.2-config	/opt/local/bin/pythonw3.2

Usually I have python27 selected as the default version, but changing that setting to python32 does not change the above directory listing.

This may also affect other python3x ports; I haven't checked whether that is the case.

Somewhat related: ticket 34326.

[cooljeanius (Eric Gallager)]

Cc Me!

[jmroot (Joshua Root)]

I think the python2 and python3 links should really be managed by port select. Where does your existing python2 link point to, BTW?

[macports.jgonggrijp@…]

python2 points to python2.7.

I think the python2 and python3 links should both exist regardless of what version is selected as the default. The Python versions are installed in parallel for a reason; you want to be able to run both and be able to (portably) indicate which one for example in a shebang line. See the PEP for a full rationale.

[larryv (Lawrence Velázquez)]

Replying to macports.jgonggrijp@…:

I think the python2 and python3 links should both exist regardless of what version is selected as the default.

I would assume that the python2 and python3 select groups would be independent of the python select group.

[macports.jgonggrijp@…]

I would assume that the python2 and python3 select groups would be independent of the python select group.

Well, that would certainly be nice. I guess this is what jmr meant, sorry for being dense. ;)

Though as far as portability (and the PEP) is concerned, it's sufficient if each link points to the latest corresponding version that is installed.

[g5pw (Aljaž Srebrnič)]

Cc Me!

[g5pw (Aljaž Srebrnič)]

Anyone already working on this? I can give a shot at splitting python_select into python{2,3}_select.

[larryv (Lawrence Velázquez)]

Replying to g5pw@…:

Anyone already working on this? I can give a shot at splitting python_select into python{2,3}_select.

I’m not sure we want to get rid of the python select group. Adding python2 and python3 is probably fine, though.

[g5pw (Aljaž Srebrnič)]

Replying to larryv@…:

I’m not sure we want to get rid of the python select group. Adding python2 and python3 is probably fine, though.

Why not? I don't suggest removing it completely, but splitting it two select groups. Then we just have to figure out how to select %prefix/bin/python.

[larryv (Lawrence Velázquez)]

Replying to g5pw@…:

Replying to larryv@…:

I’m not sure we want to get rid of the python select group. Adding python2 and python3 is probably fine, though.

Why not? I don't suggest removing it completely, but splitting it two select groups. Then we just have to figure out how to select %prefix/bin/python.

I’m not sure what you mean.

My thought is that we’d have three groups—“python”, “python2”, and “python3”—all set independently of each other.

[guillaumesalagnac]

Cc me

[guillaumesalagnac]

Cc Me!

[larryv (Lawrence Velázquez)]

Consolidating into #34326.