Automatically use pew to enter virtualenv based on path with zsh

pew.zsh

# Automatically activate pew virtualenv
function pew_venv_hook() {
    envs=("${(s/ /)$(pew ls)}")
    new_env=""
    _venv=$(basename "$VIRTUAL_ENV")
    current_env=$_venv${_venv:+}
    for env in $envs; do
        if [[ "$PWD" =~ $env ]]
        then
            new_env=$env
        fi
    done
    if [[ "$new_env" != "" ]]
    then
        if [[ "$new_env" != "$current_env" ]]
        then
            pew workon $new_env
        fi
    else
        if [[ "" != "$current_env" ]]
        then
            exit
        fi
    fi
}
chpwd_functions=(${chpwd_functions[@]} "pew_venv_hook")