This Installation steps doesn’t work for me at all. I tried on Ubuntu 16.04 & 18.04. In both cases running install.py - it does few things for some time and eventually the system just goes unresponsive. The only way to recover is to reset the machine.
The script should then prompt you for the MySQL root password and an Administrator password for the Frappe/ERPNext instance, which will then be saved under HOME/passwords.txt of the user used to setup the instance. This script will then install the required stack, setup bench and a default ERPNext instance.
$ sudo passwd frappe_dev
Above command, help to change the password of frappe_dev user
Adding frappe_dev User as sudoer and switching into it
$ usermod -aG sudo frappe_dev
$ su frappe_dev
$ cd ~/frappe-bench