Automatically activate virtualenv in Python development. (Source this file from within .bashrc)

.bash_virtenv

# From: "Automatically activate virtualenv" by Kurt Neufeld
# URL: http://www.burgundywall.com/tech/automatically-activate-virtualenv/
# Date: 16-Oct-2013
#
# Usage:
#
#   1. Create an empty .venv file in your project home: touch .venv
#   2. Put this file in your home directory: cp .bash_virtenv ~/
#   3. Include it in ~/.bashrc as follows:
#
# if [ -f ~/.bash_virtenv ]; then
#     . ~/.bash_virtenv
# fi

export PREVPWD=`pwd`
export PREVENV_PATH=
 
handle_virtualenv() {
  if [ "$PWD" != "$PREVPWD" ]; then
    PREVPWD="$PWD";
    if [ -n "$PREVENV_PATH" ]; then
      if [ "`echo "$PWD" | grep -c $PREVENV_PATH`" = "0"  ]; then
        deactivate
        unalias python 2> /dev/null
        PREVENV_PATH=
      fi
    fi
 
    # activate virtualenv dynamically
    if [ -e "$PWD/.venv" ] && [ "$PWD" != "$PREVENV_PATH" ]; then
      PREVENV_PATH="$PWD"
      workon `basename $PWD`
    fi
  fi
}
 
export PROMPT_COMMAND=handle_virtualenv
 
export VIRTUALENVWRAPPER_VIRTUALENV_ARGS='--no-site-packages'
export WORKON_HOME=~/.virtualenvs
#source `which virtualenvwrapper.sh`  # Mac only