Axis labels¶

Put the axis label where the eye arrives after the last tick.

xlabel sits below the right end of the bottom spine, its right edge lined up with the last tick label's, so the label and the tick-label row share one right margin. ylabel sits horizontal above the top tick label, left edges aligned. Those are Doumont's better graph, and both come for free (the accessor spells them set_xlabel and set_ylabel, as matplotlib does):

ax.vzs.set_xlabel("year")
ax.vzs.set_ylabel("count")

place="beside" puts the y label back level with the top tick and to its left, Doumont's good graph. Reach for it where the space above the frame is already taken, by a panel title or by the panel above: the frame modes and the warming comparison in the gallery both do.A label beside the ticks costs its own text width, and matplotlib charges it one of two ways: with bbox_inches="tight" the saved image grows to the left, while constrained_layout shrinks the axes instead. On a 5 by 3.5 inch figure, "output power (mW)" was worth 1.4 inches either way. The raised label costs a line of height and no width, and constrained layout reserves that line between stacked panels, where a hand-set subplots_adjust will not. labelpad widens the gap to the tick labels in either placement, and flush=False returns the x label to the spine's end, level with the centre of the last tick label rather than its right edge:

ax.vzs.set_ylabel("count", place="beside", labelpad=10)
ax.vzs.set_xlabel("year", flush=False)