post_install(){
	groupadd -f visdom
	chown -R :visdom /usr/lib/python2.7/site-packages/visdom
        chmod -R g+w /usr/lib/python2.7/site-packages/visdom
	echo -e "Add yourself into visdom group"
}

post_remove(){
    if ! [ -d /usr/lib/python3.7/site-packages/visdom ] ; then groupdel visdom ; fi
}