Setting the transparency and size of axis labels

The Axes label describes what the data in the figure represents and is quite important for the viewer's understanding of the figure itself. By providing labels to the axes background, we help the viewer comprehend the information in an appropriate way.

Getting ready

Before we dive into the code, it is important to understand how matplotlib organizes our figures.

At the top level, there is a Figure instance containing all that we see and some more (that we don't see). The figure contains, among other things, instances of the Axes class as a Figure.axes field. The Axes instances contain almost everything we care about: all the lines, points, ticks, and labels. So, when we call plot(), we are adding a line (matplotlib.lines.Line2D) to the Axes.lines list. If we plot a histogram (hist()), we are adding rectangles to the list of Axes.patches ("patches" is the term inherited from MATLAB®, and it represents the "patch...