I am currently practicing matplotlib. This is the first example I practice.
#!/usr/bin/python
import matplotlib.pyplot as plt
radius = [1.0, 2.0, 3.0, 4.0]
The file permissions on my virtual environment directory and my project directory were not correct and, thus, would not allow me to install the proper packages. I upadated them by running:
sudo chown user:user -R [project folder]
sudo chown user:user -R [environment folder]
In the above your should use your own usernames in place of "user". The -R recurses through all subfolders and files.