I followed these steps to set up virtualenv + virtualenvwrapper:
$ sudo apt-get install python3-pip
$ sudo pip3 install virtualenv
$ sudo pip3 install virtu
So far it was working fine but I restarted the shell
The reason is because you restarted the shell.
If you want this to work with each shell, you'll need to add these to your ~/.bashrc file:
export WORKON_HOME=~/.virtualenvs
VIRTUALENVWRAPPER_PYTHON='/usr/bin/python3'
source /usr/local/bin/virtualenvwrapper.sh
After adding this, you'll want to source ~/.bashrc so the changes take effect. You'll find that you have access to virtualenvwrapper facilities in each new shell.