Automatically enter/exit/hop pipenv virtualenvironments

.bashrc

# This will enter any virtualenvironment when there is a pipfile 
# to be found in the current directory or a directory higher up 
# in the hierarchy. It will exit if none is found, and switch if
# You cd into a different pipenv. 
# Append this to your bashrc and it will work whenever you cd around


function search_up_pipfile {
    ORIG_DIRECTORY=$PWD
    if ! [[ -z $VIRTUAL_ENV ]]; then
        TEMP_=$(echo $VIRTUAL_ENV | rev | cut -c10- | rev)
        CURR_PIPENV=${TEMP_##*/}
    fi
    while [ $PWD != "/" ]; do
        if [ -f "Pipfile" ]; then
            NEW_PIPENV=${PWD##*/}
            if ! [[ -z $CURR_PIPENV ]]; then
                if [[ $NEW_PIPENV != $CURR_PIPENV ]]; then
                    return 1
                fi
            fi
            builtin cd "$ORIG_DIRECTORY"
            return 0
        fi
        builtin cd ..
    done
    builtin cd "$ORIG_DIRECTORY"
    return 1
}

function activate_or_leave_pipenv {
    if search_up_pipfile; then
        if [[ -z $PIPENV_ACTIVE ]] ; then
            pipenv shell;
            return
        fi
    elif [[ -z $PIPENV_ACTIVE ]] ; then
        return;
    elif [ $PIPENV_ACTIVE == 1 ] ; then
        touch "/tmp/PIPENV_EXIT_DIRECTORY"
        echo "$(pwd)" >> "/tmp/PIPENV_EXIT_DIRECTORY"
        exit;
    fi
}

function cd_if_exiting_pipenv {
    if [ -f "/tmp/PIPENV_EXIT_DIRECTORY" ] ; then
        PIPENV_DIR="$(cat /tmp/PIPENV_EXIT_DIRECTORY)"
        builtin cd "$PIPENV_DIR"
        rm "/tmp/PIPENV_EXIT_DIRECTORY"
    fi
}
export PROMPT_COMMAND="cd_if_exiting_pipenv; activate_or_leave_pipenv; $PROMPT_COMMAND"