A virtual environment is simply a set of folders created in a project's directory that contain all of the necessary binaries and libraries needed to run that project.
To create a virtual environment for our blackjack game to use, open up a terminal window and move into the outer blackjack directory. Now type the following:
$ python3 -m venv env$ source env/bin/activate
This first command will create a folder called env in your blackjack folder. This folder contains everything that will be needed to run our blackjack application.
The next command tells our terminal to use the content of our virtual environment instead of the system-wide versions of Python and its packages.
To confirm this, open up the REPL ...