How to create a Python 3 Virtual Environment

virtualenv -p python3 env

Or If you have python 3.6.1:

virtualenv -p python3.6 env

https://askubuntu.com/questions/865554/how-do-i-install-python-3-6-using-apt-get

Caveats

Are you using matplotlib on MacOSX?

Well then this style venv will not work so rather use:

python3 -m venv my-venv

or

python3.6 -m venv my-venv

VirtualEnv is now built into Python3

So you can use:

    python3 -m venv env

and activate:

    source env/bin/active

Use the Superior virtualenvwrapper

Installing virtualenvwrapper:

    pip install --user virtualenvwrapper
    echo "source virtualenvwrapper.sh" >> ~/.bashrc
    source ~/.bashrc

Create a virtual env:

    mkvirtualenv --python=python3.6 superlists

Activating the environment:

    workon superlists

Deactivating an environemnt:

    deactivate

Source: