I don't believe public recipe. Therefor, this is good enough.

idempotent_install.py

from fabric.api import sudo, run, prefix

def _install_apt_if_not_installed(pkg_name):
    if not pkg_name in run('''dpkg -l | grep '{0}' | cat '''.format(pkg_name)):
        sudo('apt-get install -y {0}'.format(pkg_name))

def _install_pip_if_not_installed(venv_dir):
    def _func(libname):
        with prefix('source {0}/bin/activate'.format(venv_dir)):
            if not libname.lower() in run('''pip freeze | grep -i '{0}' | cat '''.format(libname)).lower():
                run('pip install {0}'.format(libname))
    return _func