Install virtualenv

# Step 1: Update your repositories

sudo apt-get update

# Step 2: Install pip for Python 3

sudo apt-get install build-essential libssl-dev libffi-dev python-dev

sudo apt install python3-pip

# Step 3: Use pip to install virtualenv

sudo pip3 install virtualenv

# Step 4: Launch your Python 3 virtual environment, here the name of my virtual environment will be env3

virtualenv -p python3 env3

# Step 5: Activate your new Python 3 environment. There are two ways to do this

. env3/bin/activate # or source env3/bin/activate which does exactly the same thing

# you can make sure you are now working with Python 3

python -- version

# this command will show you what is going on: the python executable you are using is now located inside your virtualenv repository

which python

# Step 6: code your stuff

# Step 7: done? leave the virtual environment

deactivate