Derived from: https://gist.github.com/codysoyland/2198913 Enables automatic activation of a virtualenv once one navigates to a directory with a .venv file whose contents are the path to a virtual environment

venv.sh

#!/bin/bash
# venv.sh
#
# Installation:
#   Add this line to your .bashrc or .bash-profile:
#
#       source /path/to/venv.sh
#
# Whenever a directory has a file called `.venv` its contents
# will be interpreted as the path to a base directory of
# a virtualenv installation, and `cat .venv`/bin/activate will
# be executed (if the current virtual env is not the same)
#
# Originally derived from: https://gist.github.com/codysoyland/2198913

function _virtualenv_auto_activate() {
    if [ -e ".venv" ]; then
        local -r _VENV_LOC=$(cat .venv)
        # Check to see if already activated to avoid redundant activating
        if [ "$VIRTUAL_ENV" != "${_VENV_LOC}" ]; then
            _VENV_NAME=$(basename ${_VENV_LOC})
            echo "Activating virtualenv \"$_VENV_NAME\"..."
            source ${_VENV_LOC}/bin/activate
        fi
    fi
}

export PROMPT_COMMAND=_virtualenv_auto_activate