Auto activate and deactivate a virtualenv environment

auto-virtualenv

#!/usr/bin/env zsh
#
# Auto activate and deactivate a virtualenv environment
# 
# Usage:
#
# Add the following code to your zshrc file. If you are using bash, change the header to bash and put the following code to your bashrc.
# ```
#     source /dir/to/auto-virtualenv
# ```
#
# How to use?
#
# Simply enter a directory with a virtualenv environment, you will find that it automatically activates it, and will automatically deactivate when exiting.
# If you don't have a theme or plugin to show whether you have activated a virtualenv environment, I deeply recommend you to uncomment the code below to give you a signal.
#
# Technical details
#
# This script scans the folder to check whether there is a subdirectory contains bin/activate (For example, it has .venv/bin/activate) and try to use it to activate the virtual environment. 
# It follows the rules of virtualenv, but theoretically speaking, any virtual environment that has this directory structure should work, including but not limited to venv and virtualenvwrapper.
#

_virtualenv_auto_activate() {
    have_not_found=true
    for folderName in $(find -maxdepth 1 -type d); do
        if [ -e "$folderName/bin/activate" ]; then
            have_not_found=false
            if [ "$VIRTUAL_ENV" = "" ]; then
                _VENV_NAME=$(basename `pwd`)
#                echo Activating virtualenv \"$_VENV_NAME\"...
                VIRTUAL_ENV_DISABLE_PROMPT=1
                source $folderName/bin/activate
                _OLD_VIRTUAL_PS1="$PS1"
                PS1="($_VENV_NAME)$PS1"
                export PS1
            fi
        fi
    done
    if $have_not_found ; then
        if [ "$VIRTUAL_ENV" != "" ]; then
#            echo Deactivating Virtualenv...
            deactivate
        fi
    fi
}

export PROMPT_COMMAND=_virtualenv_auto_activate

function chpwd(){
    _virtualenv_auto_activate
}

_virtualenv_auto_activate