Buildout and creating virtualenv under different Python versions

Question

I am looking options to integrate Python 3 tools / scripts to Plone's buildout.cfg (which targets Python 2.6). How eggs between different buildout recipes are shared? Because namely, running setup.py for Python 3 eggs would cause syntax errors in Python 2 environment.

• Can I specify Python 3 interpreter (in portable manner) for a buildout recipe like zc.recipe.egg

• Will the rest of the buildout happily eat the eggs coming under this recipe using particular Python interpreter, or would it clash with the host environment

• ... or do one have to create a virtualenv inside buildout itself to get Python 3 stuff installed

Answer 1

You can specify the executable to be used by many recipes, including zc.recipe.egg:

[python3.3]
executable = /usr/local/bin/python3.3

[py3script]
recipe = zc.recipe.egg:scripts
python = python3.3
eggs = py3script

That should install the py3script scripts with python 3.3. The key here is the python key, which points to a section that should have a executable option, which is a path to the python executable you want to use.

The executable key is then used by the easy_install module internal to zc.buildout to run the setup.py script and install the egg.