choose_venv.sh

#! /usr/bin/env bash

# A small script to choose one of more existing Python virtualenvs,
# inside $HOME/.virtualenvs. This script needs to be sourced.

function venv_activate {
  source $1/bin/activate
}

function venv_deactivate {
  deactivate > /dev/null 2>&1
}

glob="$HOME/.virtualenvs/*"

dirs=()
options=()
for dir in $glob; do
  if [ -d "$dir" ]; then
    dirs+=("$dir")
    options+=("$(basename $dir)")
  fi
done

if [ ${#options[@]} -eq 0 ]; then
  echo "ERROR: no directories ${glob} found."
  return -1
fi

# Make the user choose one
PS3='Which virtuenv do you want me to activate? Enter number: '
select opt in "${options[@]}" "Deactivate" "Exit"; do
  if (( REPLY > 0 && REPLY <= ${#options[@]} )); then
    venv_deactivate
    venv_activate ${dirs[$((REPLY-1))]}
  elif (( REPLY == ${#options[@]} + 1 )); then
    venv_deactivate
  else
    echo "Exiting without changes."
  fi
  break
done