Matplotlib is one of the best Python plotting libraries that produces publication-quality figures. Like Python, its aim is to make complex tasks simple. With over 4,800 stars on GitHub, it is also one of the most popular open source projects. It directly translates into bug fixes, user community, and general usability. It takes a bit of time to learn the package, but it is well worth the effort.
In this section, we barely scratched the surface of Matplotlib. You'll find additional resources at http://matplotlib.org/2.0.0/index.html (the Matplotlib project page) and https://github.com/matplotlib/matplotlib (Matplotlib GitHub Repository).
In the next section, we will take a look at another popular Python graph library: Pygal.