Make sure you have Python 3 installed on your machine. Then:
1.Install pipenv
sudo apt-get install pipenv
2.Go to your project directory then type following command to create virtual environment for your project.
pipenv --three
3.Activate virtual environment
pipenv shell
4. Install required packages
pipenv install {to install all packages}
pipenv install pytest {to install specific package}
5.Verify installation
pip freeze
python3 -m pytest