☯ The Busma Picayune

Many Pythons on OSX (including Python 2.4)

If you need to install many pythons on OSX, this is the definitive resource:

http://jeetworks.org/node/101

The problem is that for Pythons <=2.6, you can’t easily build them from scratch with Apple’s SDK on 64bit machines. This process is an easy alternative to getting several self-contained Python installations on your machine including Python 2.4 (which probably isn’t installed by default on your machine).

Basically:

$ cd /opt
$ svn export http://svn.plone.org/svn/collective/buildout/python
$ cd python
$ /System/Library/Frameworks/Python.framework/Versions/2.5/bin/python bootstrap.py
$ bin/buildout

Then add the following to your .profile or whathaveyou and you can switch between them:

export ALT_PYTHON_24=/opt/python/python-2.4
export ALT_PYTHON_25=/opt/python/python-2.5
export ALT_PYTHON_26=/opt/python/python-2.6
export ALT_PYTHON_27=/opt/python/python-2.7
export ALT_PYTHON_32=/opt/python/python-3.2

strip_opt_python_from_path() {
    /usr/bin/python -c "
import os
import sys
path = os.environ['PATH']
paths = path.split(os.path.pathsep)
new_path = []
for p in paths:
    if not p.startswith('/opt/python') and p not in new_path:
        new_path.append(p)
sys.stdout.write(os.path.pathsep.join(new_path))
"
}

insert-opt-python-in-path() {
    if [[ -z $1 ]]
    then
        echo "Resetting to default native Python."
        export PATH="$(strip_opt_python_from_path)"
    else
        echo "Setting alternate Python: $1."
        export PATH="$1/bin:$(strip_opt_python_from_path)"
    fi
    echo "python is now: $(which python)."
    if ! type python3 >/dev/null 2>&1
    then
        echo "python3 is not on path."
    else
        echo "python3 is now: $(which python3)."
    fi
}

unimport-alt-python() {
    insert-opt-python-in-path
}

import-alt-python-24() {
    insert-opt-python-in-path $ALT_PYTHON_24
}

import-alt-python-25() {
    insert-opt-python-in-path $ALT_PYTHON_25
}

import-alt-python-26() {
    insert-opt-python-in-path $ALT_PYTHON_26
}

import-alt-python-27() {
    insert-opt-python-in-path $ALT_PYTHON_27
}

import-alt-python-32() {
    insert-opt-python-in-path $ALT_PYTHON_32
}