virtualenv-auto-activate.sh

#!/bin/bash
# virtualenv-auto-activate.sh
# 
# Installation:
#   Add this line to your .bashrc or .bash-profile:
#
#       source /path/to/virtualenv-auto-activate.sh
#
#   Go to your project folder, run "virtualenv .venv", so your project folder
#   has a .venv folder at the top level, next to your version control directory.
#   For example:
#   .
#   ├── .git
#   │   ├── HEAD
#   │   ├── config
#   │   ├── description
#   │   ├── hooks
#   │   ├── info
#   │   ├── objects
#   │   └── refs
#   └── .venv
#       ├── bin
#       ├── include
#       └── lib
#
#   The virtualenv will be activated automatically when you enter the directory.
#   If you use git as version control, maybe you'll want to activate the correct
#   user/email for that repository, so you can add a bash script in .venv/bin
#   directory to auto activate/change the user/email for git.
#   For example:
#   .
#   ├── .git
#   │   ├── HEAD
#   │   ├── config
#   │   ├── description
#   │   ├── hooks
#   │   ├── info
#   │   ├── objects
#   │   └── refs
#   └── .venv
#       ├── bin
#       ├──── git_user.sh
#       ├── include
#       └── lib

_virtualenv_auto_activate() {
    if [ -e ".venv" ]; then
        # Check to see if already activated to avoid redundant activating
        if [ "$VIRTUAL_ENV" != "$(pwd -P)/.venv" ]; then
            _VENV_NAME=$(basename `pwd`)
            echo Activating virtualenv \"$_VENV_NAME\"...
            VIRTUAL_ENV_DISABLE_PROMPT=1
            source .venv/bin/activate
            if [ -e ".venv/bin/git_user.sh" ]; then
                GIT_USER=$(cat .venv/bin/git_user.sh | grep -o -P '(?<=user.email ).*')
                echo Activating git user for \"$GIT_USER\"
                source .venv/bin/git_user.sh
            fi
            if [ -e ".git" ]; then
                GIT_BRANCH=$(basename $(git symbolic-ref HEAD))
                echo You are in branch $(tput setaf 2) $GIT_BRANCH $(tput sgr0)
            fi
            _OLD_VIRTUAL_PS1="$PS1"
            PS1="($_VENV_NAME)$PS1"
            export PS1
        fi
    fi
}

export PROMPT_COMMAND="_virtualenv_auto_activate; $PROMPT_COMMAND"