Transparenty using virtualenv

manage.py

#!./virtualenv_python.sh

#some text

virtualenv_python.sh

#!/bin/bash
SCRIPT_PATH=$(readlink -f ${0})
PROJECT_ROOT=$(dirname $SCRIPT_PATH)
ENV_ROOT=${PROJECT_ROOT}/.env/
REQUIREMENTS=${PROJECT_ROOT}/requirements.txt
TIMESTAMP=${ENV_ROOT}.timestamp

WHEREIS="whereis -b"
PIP_BIN=/usr/bin/pip2
VIRTUALENV_BIN=/usr/bin/virtualenv2

function init_env() {
    $VIRTUALENV_BIN --python=python2 ${ENV_ROOT} ||return 1 #--no-site-packages
    source ${ENV_ROOT}/bin/activate
    $PIP_BIN install -r ${REQUIREMENTS} -E ${ENV_ROOT} ||return 1 #--upgrade
    deactivate
    touch ${TIMESTAMP}
}

if [ ! -d "${ENV_ROOT}" -o ${REQUIREMENTS} -nt ${TIMESTAMP} ]; then
    init_env
fi

source ${ENV_ROOT}/bin/activate
${ENV_ROOT}/bin/python $*
deactivate